一些英语语法问题,请告知答案并给出选择理由,谢谢.

一些英语语法问题,请告知答案并给出选择理由,谢谢.
1.seventy woman doctors 还是seventy women doctors?为什么?
2.I had my hair cut at the ____ in our hospital
A.barber B.barbers C.barber's D .barbers'
3."Do you want the pants?" "My pants _____laid in bed."
A. is B.was C.are D.being
4.I don't want to borrow Kent's big bicycle because I am too small to ride ____
A.that bicycle of him B.that bicycle of his C.that his bicycle D.his that bicycle
5.After four years in American, he got _____
A.a degree of doctor B .a doctor's degree C.the degree of a doctor D.a doctor degree
6. her house is within _____from the police station.
A.a stone's throw B. a throw of a stone C.stone's throw D.the stone's throw
7._____is really a burden to a small boy.
A.Ten pounds' weight B.Ten pounds weight C.Ten pound weights D.Ten pound weight
8."Have you ever gone water-skatting before?""Oh,yes__"
A.a dozen of time B.dozens of times C.dozens of time D.dozen of time
9.i was surprised to see _____at the concert.
A.those number of people B.that amount of people C.that number of people D.those amount of people
10.when you are at your _____end , you should not lose your head.
A.wit's B.wit C.wit's D.wit's