英语,帮忙做以下4道单选题

1.（ ）students have to work hard for twelve years before___a chance to go into a university.
A.get B.gets C.getting D.to got
c before是介词 介词后的动词为ing式
2.( )he gave me ___important advice.
A.a B.an C.one D.some
b important第一个音是元音i
3.( )two months___ a long time.
A.is B.are C.am D.be
a time不可数 只能看作单数
4( )there would be ___room for anyone as big as me.
A.don't B.no C.none D.nothing
b no作形容词讲 no room译为没有房间 don't是助动词 这里已经有be动词了不选 nothing是没有任何东西 不可选 none只能是none of 所以不能选