[1] Defendant contends the trial court erred in denying his motions for a continuance at the commencement of his trial. Defendant did not submit an affidavit in support of these motions. *183Counsel for defendant simply stated that he needed time to examine what had been produced in discovery. In particular, counsel stated that he needed additional time in order to obtain an independent chemical analysis of the white powder sold to Agent Hawkins.
Defendant contends on appeal that because the court refused to grant his motions for a continuance, he was denied his constitutional right to effective assistance of counsel in that he was not given a reasonable time to investigate and prepare his case. We disagree.
Ordinarily, a motion for a continuance is a matter within the trial court’s discretion, and thus any ruling is not reversible absent an abuse of discretion. State v. Massey, 316 N.C. 558, 342 S.E. 2d 811 (1986). However, if a motion to continue is based on a constitutional right as is the case here, then it presents a question of law which is fully reviewable on appeal. Id. See also State v. Covington, 317 N.C. 127, 343 S.E. 2d 524 (1986). “A motion for a continuance should be supported by an affidavit showing sufficient grounds for the continuance.” State v. Kuplen, 316 N.C. 387, 343 S.E. 2d 793 (1986). “A continuance is proper if there is a belief that material evidence will come to light and such belief is reasonably grounded on known facts, but a mere intangible hope that something helpful to a litigant may possibly turn up affords no sufficient basis for delaying a trial.” State v. Pollock, 56 N.C. App. 692, 289 S.E. 2d 588, appeal dismissed, 305 N.C. 590, 292 S.E. 2d 573 (1982), citing State v. Tolley, 290 N.C. 349, 226 S.E. 2d 353 (1976). Even if a trial court erroneously denies a motion for a continuance, a defendant still must show that he was prejudiced thereby. Massey, supra.
We hold that the defendant has not shown that the denial of his motions for a continuance was prejudicial error or an abuse of the trial court’s discretion. Defendant filed no affidavits in support of his motions. We could surmise that, by conducting his own analysis, defendant sought to challenge the State’s contention that the white powder sold to Agent Hawkins was indeed cocaine. However, defendant offered evidence through the direct testimony of Ronald McManus that the white powder sold to Agent Hawkins was cocaine. The nature of the substance thus was never a material issue in the case.
*184Defendant also contends that his counsel lacked sufficient time to review the transcript of the probable cause hearing for Ronald and Pam McManus, which defendant requested during discovery and received two days before trial. Additionally, defendant contends that the “record . . . reflects that the time between the indictment and . . . trial . . . was insufficient for the [defendant to prepare any defense. . . .” However, in this regard neither of defendant’s oral motions made at the commencement of trial was “supported by some form of detailed proof indicating sufficient grounds for . . . delay.” State v. Searles, 304 N.C. 149, 282 S.E. 2d 430 (1981). Defendant raises these specific contentions for the first time on appeal. Further, defendant has not shown that counsel’s performance at trial or prior to trial was in any way deficient. See State v. Teasley, 82 N.C. App. 150, 346 S.E. 2d 227 (1986). Accordingly, this assignment of error is overruled.
In a related assignment of error, defendant contends the trial court erred in denying his motion for a mistrial. Defendant argues that “because the trial court . . . erroneously denied his motion[s] for a continuance,” he was entitled to a mistrial. This contention is premised on defendant’s “continuance” argument, supra, and it fails for the reasons set forth in discussing that argument.
[2] Defendant contends the court erred in failing to grant his motion for a recess pursuant to N.C. Gen. Stat. § 15A-910(2). We disagree.
When the State called Pam McManus to testify, defendant moved for a recess arguing that the State had failed to comply with an order for discovery entered by the court on 5 November 1985. Specifically, defendant maintained that the State failed to comply with paragraph “c” of the 5 November Order which required the State to provide “[a]ll written, recorded, or oral statements of a codefendant which the State intends to offer at trial, as provided by G.S. 15A-903(b).” N.C. Gen. Stat. § 15A-903(b), however, is limited to joint trials of codefendants. Defendant acknowledges this limitation in G.S. 15A-903(b) but contends that the 5 November Order effectively modified this section, presumably by its failure to mention expressly the “joint trial” limitation. However, we disagree with defendant’s interpretation of the 5 November Order and hold that G.S. 15A-903(b) is inapplicable because defendant and Pam McManus were not tried jointly.
*185 [3] Defendant further contends that the court should have granted a recess pursuant to N.C. Gen. Stat. § 15A-1054(c) which provides as follows:
When a prosecutor enters into any arrangement authorized by this section, written notice fully disclosing the terms of the arrangement must be provided to defense counsel, or to the defendant if not represented by counsel, against whom such testimony is to be offered, a reasonable time prior to any proceeding in which the person with whom the arrangement is made is expected to testify. Upon motion of the defendant or his counsel on grounds of surprise or for other good cause or when the interests of justice require, the court must grant a recess.
When the State called Pam McManus to testify, counsel for defendant also moved for a recess pursuant to G.S. § 15A-1054 on grounds of surprise. At this point, the prosecutor, counsel for defendant and the court engaged in the following colloquy:
[Counsel for defendant]: If it please the Court, under 15A-1054, subsection c, the prosecutor has not disclosed to us any terms of any arrangements that they have made with this lady.
[State]: If Your Honor please, it appears that 15A-1054 applies when an agreement has been made. There has been no agreement made at this time.
[Counsel for defendant]: I believe we’re entitled to explore that possibility with her before she starts testifying.
[State]: I do not see where he sees that in 1054.
The Court: You’re just stating as an officer of the court that there’s been no agreement, no grant of immunity or charge reduction for this witness?
[State]: No promises have been made to her at all, if Your Honor please.
The Court: The Court will deny the motion.
On cross-examination Pam McManus testified as follows:
Q. What promises, if any, have you been told by Mr. Hawkins or anyone else related to the State about what they would do for you if you testified?
*186A. Not any at all.
Q. Have you discussed that?
A. Have we discussed it?
Q. Yes, ma’am.
A. No.
Q. Have you asked them — when was it that you contacted the State about testifying?
A. Thursday, a week ago.
Q. Did you contact them or did they contact you?
A. I contacted them.
Q. And did you ask them if they were going to give you any help?
A. I asked for protection for my life.
Q. Did you ask them if they were going to give you any help or reduction or sentence concessions in this case?
A. No.
Q. You didn’t mention that to them at all?
A. No.
She further testified:
Q. Is it not true, Ms. McManus, that the State has agreed to dismiss your case if you come up here and testify against this defendant?
A. No. It is not true.
Q. What have you hoped to gain in the way of a sentence reduction or a concession in your case from your testimony in this case?
A. I don’t hope to gain nothing but my life.
Q. Your life?
A. Yes.
*187She also acknowledged that the State had provided her with protection, food and lodging and that it had paid for two long distance telephone calls which she made.
At the close of defendant’s evidence the State recalled Agent Hawkins as a rebuttal witness. On cross-examination, Hawkins acknowledged that he had made several attempts to persuade Pam McManus to testify. In this regard, Hawkins also acknowledged that he made the same “offer” to both Pam and Ronald McManus, namely: “I can’t promise you any concessions now, but I will speak to the prosecutor about your cooperation and see about a reduction in your sentence.” Hawkins subsequently explained: “I told Ms. McManus that upon her truthful testimony in court to the statement that she did give me, that I would speak with the District Attorney regarding her assistance in this case
In State v. Lowery, 318 N.C. 54, 347 S.E. 2d 729 (1986), defendant contended that the court abused its discretion by denying his motion for disclosure by the State of all promises and inducements offered to Vincent Johnson in return for his testimony at trial, pursuant to G.S. § 15A-1054(c). Our Supreme Court disagreed and held that defendant’s rights under G.S. § 15A-1054(c) were not violated because
[(1)] there [was] no formal agreement between the State and Vincent Johnson [and (2)] defendant’s counsel was aware sufficiently in advance of trial that the witness was going to testify for the State under a hope of leniency to have brought out in cross-examination the circumstances under which the testimony was being offered.
Lowery, supra. The Court further explained:
All of the evidence produced by the defendant and Small shows that Johnson and his attorney were cooperating with the prosecution without the benefit of a formal agreement but with the hope, perhaps even an expectation based upon familiarity with the District Attorney’s practices, that if Johnson testified in the case against the defendant and Small, the State would enter into a plea bargain afterwards.
Id.
*188As in Lowery, supra, there is no evidence here of a formal agreement between the State and Pam McManus at the time she testified as a witness at defendant’s trial. However, unlike in Lowery, a law enforcement official, Agent Hawkins, promised to speak to the district attorney on her behalf and see what he could do regarding a reduction in her sentence in exchange for her “truthful” testimony against defendant.
We have stated previously that: “Promises by prosecutors of assistance or leniency, even if tentative, might be interpreted by a witness as contingent upon the nature of his [or her] testimony.” State v. Spicer, 50 N.C. App. 214, 273 S.E. 2d 521, appeal dismissed, 302 N.C. 401, 279 S.E. 2d 356 (1981). Similarly, this promise by Agent Hawkins may very well have induced Pam McManus to testify on behalf of the State and also may have influenced the nature of her testimony. Pam McManus’ credibility as a witness was an important issue in the prosecution of defendant and any promise of assistance which might be interpreted by her as contingent upon the nature of her testimony was relevant to her credibility. We thus hold that the State failed to comply with G.S. § 15A-1054(c) by not disclosing this information. However, defendant ultimately was able to attack the credibility of the testimony of Pam McManus through the testimony elicited from Agent Hawkins on cross-examination as a rebuttal witness. Further, the record reflects that the court did provide counsel for defendant with an extended lunch recess to enable him to prepare his cross-examination of Ms. McManus.
We therefore hold that the court’s failure to grant a recess in this instance does not constitute prejudicial error. We are not persuaded that had this error not been committed a different result would have been reached at trial. N.C. Gen. Stat. § 15A-1443(a). This assignment of error is overruled.
[4] Defendant contends the court erred in admitting two plastic bags containing the cocaine which Ronald McManus delivered to Hawkins (State’s exhibits two and three), because the State failed to establish the requisite chain of custody. Defendant asserts that the State failed to identify these exhibits as the objects that Ronald McManus delivered to Hawkins. In particular, defendant emphasizes that Hawkins did not place any identifying marks on the bags and that some time elapsed between delivery of the bags *189to Hawkins and the transfer of them from Hawkins to Detective Blume of the Union County Sheriffs Department. Defendant does not challenge the sufficiency of the evidence on chain of custody after the time of delivery to Blume.
We hold that the evidence presented by the State regarding the chain of custody “ ‘is sufficient to reasonably support the conclusion that the substance analyzed [was] the same as that obtained from defendant [and therefore] both the substance and the results of the analysis [were properly] admissible.’ ” Teasley, supra, quoting State v. Callahan, 77 N.C. App. 164, 334 S.E. 2d 424 (1985). In particular, Hawkins testified that he received the two bags containing white powder from Ronald McManus on the morning of 18 June and “kept [them] on [his] person . . .” until he delivered them to Blume. Blume testified that he received the bags from Hawkins on the morning of 18 June and that he marked the date and initialed them. Hawkins testified that he was absolutely certain that exhibits two and three were the same bags which he had turned over to Blume on 18 June. As in Teas-ley, supra, any weaknesses here in the chain of custody regarding the actions or inactions of Hawkins go to the weight rather than the admissibility of the evidence. This assignment of error is overruled.
Defendant contends that on three occasions the court “infringed on his right to full and effective cross-examination of the State’s witness Pam McManus.” Our review of these exceptions reveals no prejudicial error.
The scope of cross-examination is limited to those matters which are relevant to the issues before the jury. N.C. Gen. Stat. § 8C-1, Rule 611(b) of the N. C. Rules of Evidence; State v. Hosey, 79 N.C. App. 196, 339 S.E. 2d 414, cert. granted, 316 N.C. 382, 342 S.E. 2d 902 (1986). Further,
The wide latitude accorded the cross-examiner “does not mean that all decisions with respect to cross-examination may be made by the cross-examiner.” . . . Rather, the scope and duration of cross-examination rest largely in the discretion of the trial judge. . . . “The judge has discretion to ban unduly repetitious and argumentative questioning, as well as inquiry into matters of only tenuous relevance.” [Citations omitted.]
*190 State v. Satterfield, 300 N.C. 621, 268 S.E. 2d 510 (1980).
Defendant contends the court improperly sustained the State’s objection to his question regarding the kind of medication prescribed for the witness while she was “coming out of [her cocaine] addiction.” Defendant also asserts that the court improperly sustained the State’s objection to his question concerning the distance between the witness’ house and downtown Monroe. The record indicates that the witness had already testified substantially on these matters during cross-examination.
Defendant lastly contends that the trial court improperly sustained the State’s objection concerning the witness’ clarity of mind since 18 June 1985. Assuming, arguendo, that this contention has some merit, defendant was not prejudiced thereby because the witness testified that cocaine caused her to lose control over her mind and that she had used cocaine after 18 June 1985. In sum, “We cannot say from an examination of this record that the [court] abused [its] discretion or deprived defendant of a fair trial by the rulings here challenged.” Satterfield, supra. Accordingly, this assignment of error is overruled.
Defendant contends the court erred in refusing to grant his motion to strike all uncorroborative portions of a written statement from Pam McManus which was read to the jury by Agent Hawkins. The State offered the statement to corroborate the witness’ testimony. Defendant neither moved to strike or exclude any specific part of the statement nor called “to the attention of the trial court the objectionable part” of the witness’ statement. State v. Britt, 291 N.C. 528, 231 S.E. 2d 644 (1977). Accordingly, defendant may not now object on appeal to the introduction of specific portions of the witness’ statement. N.C. Gen. Stat. § 8C-1, Rule 103(a)(1); Britt, supra. See also State v. Brooks, 260 N.C. 186, 132 S.E. 2d 354 (1963). In any event, the portions of Ms. McManus’ statement which defendant asserts are noncorroborative actually represent slight variations which do not render it inadmissible. Britt, supra. This assignment of error is overruled.
Defendant contends the court erred by admitting, over his objection, evidence “which lacked logical relevance and created the substantial danger of unfair prejudice to the defendant.” Specifically, defendant asserts that the court should not have admitted evidence that: (1) Agent Hawkins had previously pur*191chased cocaine from Ronald McManus before the 17-18 June transaction; (2) Agent Hawkins told McManus on 17 June that he wanted to purchase additional amounts of cocaine; (3) Pam McManus had conversations with defendant concerning cocaine when she first met him; (4) Defendant and his wife were present at the McManuses’ house the night Agent Hawkins first contacted them about purchasing cocaine; (5) Defendant kept “scales” at his residence; and (6) Defendant and Ronald McManus had a fist fight approximately nine years earlier. Defendant argues that this evidence should have been excluded under N.C. Gen. Stat. § 8C-1, Rules 401, 402 and 403. We disagree.
Regarding the first two items enumerated above, defendant has waived his right to raise on appeal his objections to this evidence because the same evidence was later admitted without objection. State v. Chapman, 294 N.C. 407, 241 S.E. 2d 667 (1978). Ronald McManus testified without objection that he sold cocaine to Agent Hawkins around 13 June and that Hawkins asked to purchase additional amounts of cocaine from him on 17 June. “Where evidence is admitted over objection, and the same evidence has been previously admitted or is later admitted without objection, the benefit of the objection is lost.” State v. Whitley, 311 N.C. 656, 319 S.E. 2d 584 (1984). Although the North Carolina Rules of Evidence do not address this rule explicitly, there is no indication that they are intending to change it. 1 Brandis on North Carolina Evidence § 30 (1983 Supp.). Brandis suggests that this rule simply illustrates the provision in N.C. Gen. Stat. § 8C-1, Rule 103(a) which requires an objecting party to show that the court’s ruling affects a substantial right. Id.
[5] Regarding items 3, 4 and 5 above, we hold that this evidence was clearly admissible under G.S. 8C-1, Rules 401 and 403. In general, evidence having any tendency to make the existence of any fact that is of consequence to the determination of the action more probable or less probable than it would be without the evidence is relevant. G.S. § 8C-1, Rule 401. Relevant evidence may be excluded if its probative value is substantially outweighed by the danger of unfair prejudice, conclusion of the issues, or misleading the jury, or by considerations of undue delay, waste of time, or needless presentation of cumulative evidence. G.S. § 8C-1, Rule 403. Unfair prejudice has been defined as an undue tendency to suggest decision on an improper basis, commonly, *192though not necessarily, an emotional one. Commentary to N.C. R. Evid. 403. Whether or not to exclude evidence under Rule 403 is a matter within the sound discretion of the trial judge. State v. Mason, 315 N.C. 724, 340 S.E. 2d 430 (1986).
The State prosecuted defendant on the theory that he was an aider and abettor in the commission of the crimes charged. This Court has stated that:
Circumstances to be considered in determining whether a defendant aided and abetted the actual perpetrator of a crime include the following: (1) the relationship of the defendant to the actual perpetrator; (2) the motive tempting the defendant to assist in the crime; (3) presence of the defendant at the time and place of the crime; and (4) conduct of the defendant both before and after commission of the crime. [Citation omitted.]
State v. Cassell, 24 N.C. App. 717, 212 S.E. 2d 208, appeal dismissed, 287 N.C. 261, 214 S.E. 2d 433 (1975). Further, “the charge of possession with intent to sell involves guilty knowledge, which in drug cases ordinarily must be shown by circumstantial evidence indicating involvement in drug traffic.” State v. Shaw, 53 N.C. App. 772, 281 S.E. 2d 702, disc. rev. denied, 304 N.C. 590, 289 S.E. 2d 565 (1981).
In light of the charges against defendant and the theory of prosecution we hold that this evidence was relevant in that it tended to show defendant’s motive, presence, and relationship to the actual perpetrators, as well as guilty knowledge. See Shaw, supra. Further, we perceive no danger of unfair prejudice that substantially outweighed the probative value of this evidence. State v. Teasley, supra.
Lastly, we hold that the evidence concerning a prior altercation between defendant and Ronald McManus, though arguably not relevant, was not sufficiently prejudicial as to affect the outcome of the trial. Accordingly, this assignment of error is overruled.
[6] Defendant contends the court erred by allowing Agent Hawkins to testify concerning statements made by Ronald and Pam McManus and by allowing Pam McManus to testify about statements made by defendant. Specifically, defendant contends these *193statements by defendant’s co-conspirators, although made in furtherance of the conspiracy, were inadmissible because “the State failed to demonstrate that a conspiracy existed between the defendant and the codefendants before the State’s witnesses testified to hearsay statements.” (Emphasis added.) We disagree.
Defendant acknowledges that G.S. § 8C-1, Rule 801(d) provides that hearsay statements made by a co-conspirator in furtherance of the conspiracy are admissible when offered “against a party . . .” as an exception to the hearsay rule. Further, our Supreme Court has stated:
When the State shows a prima facie conspiracy, the declarations of the co-conspirators in furtherance of the common plan are competent against each of them. . . . This is so even where the defendants are not formally charged with a criminal conspiracy. [Citations omitted.]
State v. Covington, 290 N.C. 313, 226 S.E. 2d 629 (1976).
The State’s evidence here showed that defendant and the Mc-Manuses were carrying out a plan or agreement to possess cocaine with the intent to sell and deliver it and a plan or agreement to sell and deliver it. This evidence established a prima facie conspiracy. See id. Further, while a prima facie case of conspiracy must be made out before the close of the State’s evidence, “our courts often permit the State to offer the acts or declarations of a co-conspirator before the prima facie case of conspiracy is sufficiently established.” State v. Polk, 309 N.C. 559, 308 S.E. 2d 296 (1983). The trial court thus properly admitted the statements by defendant’s co-conspirators. This assignment of error is overruled.
[7] Defendant contends the trial court erred in denying his motions to dismiss, at the close of all the evidence, the charges of possession of cocaine with intent to sell and deliver and sale and delivery of cocaine in violation of G.S. § 90-95(a)(l). Relying on State v. Parker, 268 N.C. 258, 150 S.E. 2d 428 (1966) and State v. LeDuc, 306 N.C. 62, 291 S.E. 2d 607 (1982), defendant contends that:
The State’s entire case rested on the inference that since the defendant drove his truck to the house of Mr. McManus, picked up Mr. McManus as a passenger outside the McManus *194house, and drove the truck away from the house, the defendant went to Charlotte with Mr. McManus and purchased an ounce and a half of cocaine.
However, through the testimony of Pam McManus, the State offered direct evidence of defendant’s participation in the crimes charged. Pam McManus testified that on the night before Agent Hawkins bought the cocaine, she went to defendant’s house and requested that he lend her husband his truck or take him to get some cocaine. Defendant followed Pam McManus back to her house where Ronald McManus entered defendant’s truck and the two left. When the two returned, Ronald McManus indicated to his wife, with defendant present, that he and defendant had gone to Charlotte, and purchased cocaine there. Pam, Ronald and defendant returned to defendant’s residence to use more cocaine and weigh out cocaine on a scale in the kitchen. Ronald McManus then left to deliver cocaine to Hawkins. The foregoing evidence shows that the State’s case did not rest on inference but rather on direct evidence of defendant’s participation. Defendant’s argument thus is without merit. Accordingly, this assignment of error is overruled.
[8] Defendant contends the court erred in sentencing him for his conviction for sale and delivery of cocaine to the maximum term of ten years. Specifically, defendant contends that the sole aggravating factor found, his prior convictions, is not sufficient to “support such a severe sentence.” However, “[e]xcept for maximum sentence limitations in G.S. 14-1.1, the severity of a sentence imposed pursuant to the Fair Sentencing Act, insofar as it is based on a weighing of aggravating and mitigating factors is within the discretion of the judge.” State v. Salters, 65 N.C. App. 81, 308 S.E. 2d 512 (1983), disc. rev. denied, 310 N.C. 479, 312 S.E. 2d 889 (1984). As in Salters, we hold that the court “properly found that this aggravating circumstance, in the absence of any factor in mitigation, warranted the imposition of a term that exceeded the presumptive.” Id. Accordingly, this assignment of error is overruled.
No error.
Judges BECTON and ORR concur.