[解题导语] 本文是一篇科技说明文，介绍了(CAT scans)电子计算机X线断层扫描在医学上的应用和优点。
5．What is NOT true of a CAT scan?
A．It is safer than regular Xrays.
B．It makes use of computer techniques.
C．It can stop the action of an organ for a short time.
D．It can give clear pictures of active，moving body parts.
