位于放射治疗范围内的牙齿拔除时间是（）

A.放射治疗前

B.放射治疗结束后速拔

C.放射治疗前后均不应拔

D.放射治疗后1个月

E.放射治疗后1周即可

The Flinders bar and the quadrantal spheres should be tested for permanent magnetism at what interval（）.

A.They are not subject to permanent magnetism; no check is necessary

B.Semiannually

C.Annually

D.Every five years