We should make____a rule for us that the last to leave the classroom shall turn the light off.

________ the way, did you meet Danny ______ your way home yesterday afternoon? — Yes, I did. [ ]

Li Ming is in poor health. He should pay more attention _________ exercise.

He has two pets. One is a dog, ______ is a cat.

What do you think of this book?— Good indeed. It ________ many problems we have in our study.