1、Paul does nothing but __ all day long

1、Paul does nothing but __ all day long
A.play B.to play C.to wait D.wait
2、Mpw we cpi;d mpt dp amutjomg nit __ for him here
A.waited B.waiting C.to wait D.wait
3、The lost child desired nothing but __ home
A.go B.to go C.going D.went
请问这三题各选什么 有什么区别 能不能顺便帮忙解释一下nothing but 和不定式..
第二题尴尬了.Now we could do anything but __ for him here
A.waited B.waiting C.to wait D.wait