Tiring as it might be the military training the best opportunity to make lifelong frien

问题补充：

Tiring as it might be, the military training the best opportunity to make lifelong friends.

A. is believed to be

B. believes as

C. is believed to being

D. believes

答案：

(答案→)A. is believed to be

B. believes as

C. is believed to being

D. believes

解析：句型考查题。Sth be believed to do… “据认为…”句意：虽然累然而军训被认为是结交终身朋友的好机会。