We _____ have proved great adventurers, but we have done the greatest march ever made in the past ten years.

A. needn't

B. may not

C. shouldn't

D. mustn't

既收敛固涩又补益肝肾的药是（）

A.煅龙骨

B.牡蛎

C.山茱萸

D.糯稻根须

E.莲子