1.Carol said the work would be done by October,___personlly

1.Carol said the work would be done by October,___personlly I doubt very much.
答案是D为什么不选B
A.it B.that C.when D.which
2.-Why don't we take a little break?-Didn't we just have___?
答案是B为什么不选A
A.it B.one C.that D.this
3.-___has just come in?-It's Mr.Green,our headmaster.答案是C为什么不选A
A.Who is that B.Who that is C.Who's it that D.Who it is
4.___I was free that evening.答案是B为什么不选B或者C?
A.It happened to B.It happened that C.That happened D.It was happened that