【题目】What is known to all is that up to now China has made a great ___________ to preserving the peace.
A.conclusion
B.comment
C.campaign
D.contribution

【答案】D
【解析】考查名词辨析。 conclusion意为：结论；comment意为：评论；campaign意为：战役；contribution意为：贡献。句意：众所周知的是，到目前为止中国维护和平做出了很大地贡献，根据句意可知选项D正确。故选D。