This math problem is too difficult. Can you show me________, George?
A. what to work out B. to work it out
C. how to work it out D. how to work out it
－Where is your father ?
－He is at work . He always has lots of work __________ .
A. do B. to do C. doing D. does
We are supposed ______ the lost child at once.
A. find B. to finding
C. finding D. to find
If prices rise too high, the government has to do something _________ it.
A. stop B. stopped C. stopping D. to stop
—I didn't hear you come in just now.
— That's good.We tried ________ any noise，for you were sleeping.
A. not make B. not to make C. to make D. making
Tony, remember________ with your mouth full of food.
A. to talk B. not to talk
C. talking D. talk
