--Why are the windows so dirty?
--Because we_________them for a long time.
A. have cleaned B. haven't cleaned C. didn't clean
Hurry up, everyone ________ for you.
| A．waited | B．is waiting | C．waits | D．will wait |
Trees __________ on Tree Planting Day only.
| A．shouldn’t be planted | B．should not plant |
| C．shouldn’t be planting | D．not be planted |
Sorry, smoking ________ here.
| A．isn’t allowed | B．doesn’t allow | C．didn’t allow | D．wasn’t allowed |
Some rules _________ to stop people from polluting the environment.
| A．must make | B．must be made | C．must made | D．be made |
I can’t go to the party, because I have to ________ my daughter at home.
| A．take away | B．take off | C．take care of | D．take out of |