
372 S.E.2d 729 (1988)
91 N.C. App. 577
STATE of North Carolina
v.
Daris Dexter ALVERSON.
No. 8817SC199.
Court of Appeals of North Carolina.
October 18, 1988.
*730 Atty. Gen. Lacy H. Thornburg by Asst. Atty. Gen. Kaye R. Webb, Raleigh, for State.
Daniel K. Bailey, Reidsville, for defendant, appellant.
HEDRICK, Chief Judge.
Defendant first contends the trial court erred by expressing its opinion as to his guilt in front of the jury. He bases this argument on 39 exceptions noted in the record. During the trial, the trial judge on numerous occasions sustained objections by the State that defendant's counsel was leading witnesses on direct examination. He admonished defendant's counsel by making comments such as "I can't let you testify for your own witness," and "[y]ou may ask when it was, that is an easy question, when, where, why and what." Defendant argues the trial judge did not admonish the State's attorney when he led witnesses, and that this expressed an opinion as to defendant's guilt.
The trial judge on other occasions admonished defendant's counsel for "badgering the witness" and "arguing" on cross-examination. Defendant contends that these comments and questioning of witnesses by the trial judge are examples of favoritism and partiality on the part of the trial judge. We disagree.
Under G.S. § 15A-1222, the judge "may not express during any stage of the trial, any opinion in the presence of the jury on any question of fact to be decided by the jury." It is the right and duty, however, of the trial judge to control examination and cross-examination of witnesses. State v. Turner, 66 N.C.App. 203, 311 S.E. 2d 331, disc. rev. denied, 311 N.C. 768, 321 S.E.2d 156 (1984). The trial judge may also ask a witness questions for the purpose of clarifying testimony. State v. Jackson, 306 N.C. 642, 295 S.E.2d 383 (1982).
We have reviewed all the exceptions defendant has noted in the record in support of his argument, and find that the trial judge's comments did not express an opinion as to defendant's guilt. All of the comments were routinely made in the course of the right and duty the trial judge had to control examination and cross-examination of witnesses, and the questions asked were for clarification purposes. Even if any of the trial judge's comments or questions were improper, defendant has not shown that he was prejudiced. See State v. Lofton, 66 N.C.App. 79, 310 S.E.2d 633 (1984). This argument has no merit.
Defendant's second argument is that "the trial court erred in not allowing defense counsel to review the entire investigative file compiled in this case...." G.S. § 15A-904 provides that the Criminal Procedure Act "does not require the production *731 of reports, memoranda, or other internal documents made by the prosecutor, law-enforcement officers, or other persons acting on behalf of the State in connection with the investigation or prosecution of the case...." In this case, the investigative file requested by defendant consisted of internal documents made by law enforcement officers, and none of it was subject to discovery by defendant. This argument is without merit.
Defendant's third argument is that the trial court erred by not allowing cross-examination of the prosecuting witness about her sexual activity with her boyfriend. Under G.S. § 8C-1, Rule 412, the sexual behavior of the prosecuting witness is irrelevant unless the behavior is as follows:
(1) Was between the complainant and the defendant; or
(2) Is evidence of specific instances of sexual behavior offered for the purpose of showing that the act or acts charged were not committed by the defendant; or
(3) Is evidence of a pattern of sexual behavior so distinctive and so closely resembling the defendant's version of the alleged encounter with the complainant as to tend to prove that such complainant consented to the act or acts charged or behaved in such a manner as to lead the defendant reasonably to believe that the complainant consented; or
(4) Is evidence of sexual behavior offered as the basis of expert psychological or psychiatric opinion that the complainant fantasized or invented the act or acts charged.
In this case, defendant wanted cross-examination of the prosecuting witness because he speculated she was motivated to accuse him of rape because she was pregnant by her boyfriend. This does not fall under an exception to Rule 412, and therefore is not relevant. The trial court was correct when it did not allow cross-examination of the prosecuting witness.
Finally, defendant contends the trial court erred by sentencing defendant based upon improper aggravating factors. The record indicates that the trial judge found as an aggravating factor that defendant had a prior conviction or convictions for offenses punishable by more than 60 days confinement. No mitigating factors were found. The trial judge, in his sound discretion, may increase sentences from the presumptive term upon finding aggravating factors. State v. Ahearn, 307 N.C. 584, 300 S.E.2d 689 (1983). A single aggravating factor is sufficient to support a sentence greater than the presumptive. State v. Upright, 72 N.C.App. 94, 323 S.E.2d 479 (1984), disc. rev. denied, 313 N.C. 513, 329 S.E.2d 400 (1985). The weight attached to a particular aggravating factor is within the discretion of the trial judge. State v. Salters, 65 N.C.App. 31, 308 S.E.2d 512 (1983), disc. rev. denied, 310 N.C. 479, 312 S.E.2d 889 (1984). In this case, there has been shown no abuse of discretion, and the trial judge's imposition of a 35-year sentence based on the aggravating factor found was not error.
We hold defendant had a fair trial, free from prejudicial error.
No error.
ARNOLD and COZORT, JJ., concur.
