高二 英语 English problem 请详细解答,谢谢! (6 9:56:55)

高二 英语 English problem 请详细解答,谢谢! (6 9:56:55)
1.Don't  hesitate__________me  if   you haveany questions.
Aasking    B asks      C to ask       D asked 
2.The  idea puzzled   mo so much that I stopped for a few seconds to try to _________.
A make  it up   B make  it  off   C make   it   up      D make  it  over
3.Without    facts,we   cannot    form  a  worthwhile   opinion foe we need to have factual knowledge___________ our thingking.
A which  to  base  upon  B which to be based on C upon which to base  D to which to be based
今天问题有点多 谢谢各位的详细解释啦

1 A 固定搭配 hesitate do do sth.犹豫做.
2 所给答案可能存在问题 为什么A C的选项是相同的
3 D 答案里首先包含了base on 这一短语 至于用被动的原因 正确的语序应为 our thinking base on factual knowledge