Most of the choices appear to be ones that you are familier with, but after taking second look, you will find that they are different.

We often cut things _____ scissors. [ ]

We knock _____people’s doors, and they usually give us some candy ______ a treat.[ ]

.It was obviously that the man ______ driving on the free way for almost an hour when he ______ that he must come back.

This kind of bamboo is not suitable_____pandas _____ eat.[ ]