—I'm busy with my schoolwork these days.

—That's great！You won't get good grades ________ you study hard.

A. until B. because C. unless D. though

Don't worry.Your son is old enough to look after ________.

A. myself B. yourself C. herself D. himself

Finally，we all decided to ________ a concert for the coming New Year's Day.

A. organize B. draw C. serve D. forward

I'm afraid we don't have enough rooms for our guests ________.

A. to live B. to live in C. living in D. to living

It's best ________ about personal things in the office.Your work is more important.

A. not to talk B. to not talk C. not to talking D. to not talking

—My sister is going to eat more vegetables. —If she _______ so, she will lose weight.

A. does B. doesn’t C. will D. won’t

All the students in Class 5 will climb the mountain if it _______ rain tomorrow.

A. won’t B. don’t C. didn’t D. doesn’t

The sports meeting will continue ___it rains this afternoon.

A. if B. since  C. as soon as  D. unless

Sorry，I took your schoolbag by_______.

A. mistake B. mistakes C. mistook D. mistaken

—I’m going for a summer camp in Qingdao next month.

— ______!

A. What a pity B. Not at all

C. Don’t worry D. Have a good time