有几道题不大明白 希望能够解释分析下选择的理由..

有几道题不大明白 希望能够解释分析下选择的理由..
1.A man of less courage____to stand up to such a complicated situation.
A.would not have dared B.could not have dared
C.will not dare D.did not dare
A..
怎么分辨这个就是虚拟了.
2.Computers are already widely used in industry and in universities and the time may come when it____possible for ordinary people to use them as well.
A.is B will be
正确答案B...
为什么不是A..不是主将从现吗 不是很明白..
3.There are several possible explanations for the greater job stability in JAPAN______ the great job mobility in the United States.
A.contrary to B.in contrast to
正确答案是B..为什么..
这两个词用法我没搞清..
4.Whether to go to college is optional ___that no studeng is required to do so as he is required by law in most states of America to go to high school.
A in a sense B in the sense
这题应该选“从某种意义上说”咯 那是A 还是B
5.Though she could hardly make ends meet herself ,she managed to save_____she could out of her slim salary to help her brother to go to school.
A how little money B such little money C so little money
D what little money
这题选D 不太明白原因 ...
有点多,..