for和of用法的区别

题目

for和of用法的区别
1.It's necessary ______us to master a language.
2.It's unwise ______them to refuse our help.
3.It is very important _____us to study some rules.
4.It is unpracticable ______us to finish such a difficult task
in such short time.
5.It's wrong _____a person to think only of himself.
哪些用of哪些用for,请说明原因,我老分不清楚.

答案

1.It's necessary ___for___us to master a language.2.It's unwise ___of___them to refuse our help.3.It is very important ___for__us to study some rules.4.It is unpracticable ___for___us to finish such a...