1.You'd better_____things_____if you dont't know how to deal with them.( )
A.to leave...alone B.leave...alone
C.to take...alone D.take...alone
2.Attempts to_____this ole system have been made in every presidential election in the past one hundred years,but the system has srrvived all as salutes.( )
A.break down B.break in C.break up D.break through
3.Such_____the case,there were no grounds to justify complaints.( )
A.was B.being C.would be D.had been
4.All can say _____that he has always been good to me .( )
A.is B.was C.are D.were
以上几道题，急求!请老师帮忙分析详解，并帮我翻译出来好吗？

1.选 B.leave...alone. You'd better后一般用动词原形.
如果你不知道处理这些事情的话最好先把它放在一边.

2.选 D.break through. 一百年来,每届总统大选都企图打破
这一常规,但最终它不是作为礼节保留下来了.

3.选 A.was. 情况就是这样,没有理由说明亮相抱怨是正当的.

4.选 A.is. 我要说的是, 他总是对我那么好.