问题补充:
Everyone should make a contribution the environment.
A. to protect
B. to protecting
C. protects
D. protected
答案:
A. to protect
(答案→)B. to protecting
C. protects
D. protected
解析:考查非谓语动词.句意:每个人应该为保护环境做出一份贡献.make a contribution to doing sth表示全力一赴做某事,to是介词后面接名词或者动名词作宾语,动名词表示抽象动作,故选B.。