单项选择

单项选择
1、（ ）I hear the new shopping mall gives a discount ________ 50%.
A、up B、to C、up for D、up to
2、-May I go home now?
-No,you ________.You _________ finish your homework first.
A、needn't;may
B、can't must
C、mustn't;can
D、may not;should
3、The talk is ________to be _________ Saturday morning.It's dangerous.
A、likely;on B、possible;in C、able;on D、like;on
4、If you can't remember the words quickly,you need _______ to help you.
A、to more exercise B、many exercise
C、more exercises D、to exercising
说明理由,
PS:小弟刚刚注册,请各位多多关照,多多包涵.当然,最佳答案我会在两天内选出来的.