Although you may meet some difficuIties,you should never .
______ your English teacher ______ you ?
They were talking about the persons and things _______ they saw in the factory.
Not only the students but also their teacher_______ the Great Wall before.
It is impossible for ______ little children to do ______ much work within 20 minutes.
He has spent as much time as he has _______ English in the morning.