题目内容：

英语用适当的介词填空
l will be [ ] you if you have trouble
themath problem is very hard [ ] me

优质解答

l will be [ for ] you if you have trouble.
如果你有麻烦,我会支持你
be for sb:站在某人一边,支持某人
the math problem is very hard [ for ] me.
be hard for sb:对某人很难.
数学题对我来说非常难.