—I think trees ____________ twice a week in such hot weather.
—Yes, I agree. Or they may die without water.
| A．must water. | B．are watered. |
| C．must be planted. | D．must be watered. |
--Why is she at Xiao Ying’s home?
--_________ they are friends.
| A．So | B．For | C．Since | D．Because |
We are ________ a school trip.
| A．in | B．on | C．at | D．for |
---When is Christmas?
--- It’s _____ December 25.
| A．in | B．to | C．on | D．at |
---Is Nancy doing her homework?
-----___________.
| A．No, she is | B．No, she isn’t | C．Yes, she does | D．Yes, she isn’t |
What ___________?
| A．does happen | B．is happening | C．do happen | D．are happening |