Question

youcanasktheteacherforhelp

------the teacher for help if you can't work out
the problems.A.Ask.B.Asks.C.asking.D.to ask.为什么选A?

Answer 1

祈使句：
等于：
If you can't work out,ask the teacher for help.
如果你解不出来,问一下老师.
Come here tomorrow if you are free.
明天有空的话,请来这里.