George always does his best in school, and that’s ______ I like about him.
He went to Beijing and returned ____ three days.
He will come ____ three days.
The PLA man saved the boy ____ death.
The group is made up____five students. And they are studying hard to make up____ the lost time.
The boy is waiting ____ his sister and they will go to the hospital to wait ____ their sick mother.