If you try to sit on two chairs, you will fall them For life, you must choose one chair. [ ]

The farmer took an advantage _____ the good weather _____ paint the shed (小屋).[ ]

Did you see Dr Ma yesterday afternoon? —When I got to his office, he ______. So we just talked little.

new bridge has been built overChangjiang River in Huangshi.

Why is the classroom so dirty?—Sorry，sir. Ityesterday, We forgot to do it.