Dick often plays a trick _____ others. [ ]

After class, we always have a good time ________ to each other.

________ have you become so good at English this term ?—By studying grammar and reading English novels.

Look at these factories. I hate them. They____ many rivers here. –Yes. Something ______ to stop the pollution.

I have made ______ clear _______ I have nothing to do with the accident.