—Mr Wang was caught in a snowstorm yesterday.

—I have known that，and_______his new car was completely 　destroyed.

A．hopefully

B．fortunately

C．thankfully

D．unfortunately

牙体预备时，为保护牙髓所采取的措施，错误的是（）。

A.轻压磨切

B.水雾冷却

C.短时切割

D.分次完成

E.间歇切割