问题
选择题
Chang’e2 did many experiments, ______ I think are of much help for knowing space.
A．which
B．what
C．when
D．where
答案
答案：A
题目分析：考查定语从句。“嫦娥二号”做了许多试验，我认为这些试验对人们了解太空很有帮助。I think是插入语，可忽略，定语从句缺少主语，排除C、D；what不引导定语从句。故选A。