21. Don’t pour water on his plan. We should encourage him.
| A．hot | B．cool | C．warm | D．Cold |
Many people can’t learn any lessons from the mistakes they’ve made ________ they get hurt somehow.
| A．whether | B．as | C．if | D．unless |
—Have you been to the United States?
—Yes, only once. I ________ there only for seven days.
| A．have stayed | B．was staying |
| C．stayed | D．had stayed |
Would you please keep silent? The weather report ________ and I want to listen.
| A．is broadcast | B．is being broadcast |
| C．has been broadcast | D．had been broadcast |
The girl was very naughty. She hid her mother’s wallet without anyone ________ where it was.
| A．knows | B．knew | C．known | D．knowing |
We all believe that the project, if _______ according to plan, will definitely work out well.
| A．carrying out | B．being carried out |
| C．carried out | D．to be carried out |