—_____ I come back before 6 o'clock?

—No, you _____. But you _____ be back later than 7 o'clock. [ ]

A. Need; must; must

B. May; mustn't; can't

C. Can; can't; can't

D. Must; needn't; can't

贝克曼梁测定路基路面，沥青路面厚度在（）可不进行温度修正。

A.小于等于5cm

B.小于等于10cm

C.大于等于5cm

D.大于等于10cm