since there is not much time left,i will tell you about it in...
a,detail
b,brief
c,mcommon
d,total
2 you always take ...great trouble to help me when i am in ..trouble
a,a;/
b,/;/
可trouble不是可数吗?
3,a series of speeches...given by the teacher
a,has been
b,have been
一系列东西终究不还是复数吗?