This is a difficult and stressful job, but one _____ you can really help people

You can only be sure of_________ you have at present; you cannot be sure of something _____ you might get in the future.

I think Liu Mei sings best in our class. No one else sings .

ebrate the New Year, the studentsstayed in the classroom after school, _____ the performances and ______ theroom.

May I have a cat at home, Dad—Yes, you can. But you must know how to ____________ it.