2.the dining-room is too crowded to have___for us to come in.Shall we go out for dinner?

2.the dining-room is too crowded to have___for us to come in.Shall we go out for dinner?
A.a room B.any room C.rooms D.the room
这个ROOM是作空间将的 ANY可以用来修饰不可数的抽象名词么?
3.It's bad___to speak with your mouth full of food.
A.manner B.way C.manners D.thing
这个我选的是C···因为刚讲过某些以S结尾的名词一般只用作复数MANNERS就是其中之一 具体为什么这么选我不知道···为什么不能选 B
4.the rescue team made every___to find the missing climbers.
A.energy B.effort C.force D.power
这题我不知道如何去选 应该比较复杂 每个词都有用法上的区别 也没差到···请教
5.they said they would have___in collecting 200 dollars in one day.
A.some difficulties B.any difficulties C.some difficulty D.any difficulty
我记得difficulty是困难；困境的意思 是抽象名词 但当它表示具体的事情的时候是可以做可数名词的