We’ll do what we can our environment.A. protect　B. to protect　C. be protected　D. be prote

问题补充：

We’ll do what we can our environment.

A. protect

B. to protect

C. be protected

D. be protecting

答案：

A. protect

(答案→)B. to protect

C. be protected

D. be protecting

解析：句意：我们要尽我们所能的来保护我们的环境。本句中what we can是宾语从句，不定式作宾语补足语表示具体的将要进行的动作，结合语境可知选B.