Looking after very young children _____ be very annoying sometimes, but you’ll get used to it after a while.
| A．must | B．should | C．shall | D．can |
32. –Why, I couldn’t get you on the phone this morning.
--We _____ tennis in the yard when you called.
| A．must be playing | B．could be playing |
| C．must have played | D．must have been playing |
31. Tom as well as his classmates _____ Japanese in Japan.
| A．are studying | B．have studied | C．studies | D．Study |
30. Let Harris play with your toys as well, Clare. You must learn to _____.
| A．support | B．care | C．share | D．Spare |
29. New ways _____ to prevent the river _____.
| A．have found out, from polluting |
| B．have found, from being polluted |
| C．have been found out, from being polluted |
| D．have been found, from being polluted |
28. The first thing she did _____ up to her trainer and thanked her.
| A．was go | B．was going | C．and went | D．Go |