31. You see the lightning _____ it happens, but you hear the thunder later.
| A．for an instant | B．on the instant | C．in a instant | D．the instant |
The harder you work,____________.
| A．the greater progress you'll make |
| B．the greater you'll make progress |
| C．you'll make the greater progress |
| D．you'll make greater progress |
--Do you like the material?
--Yes, it ___________ very soft.
| A．is feeling | B．felt | C．feels | D．is felt |
--Where is Xiao Wang?
--I don’t know. He__________ be in the library.
| A．can | B．must | C．might | D．may |
Bread and butter____________ for breakfast in many Chinese homes nowadays.
| A．serve | B．servers | C．is served | D．are served |
Is this the restaurant ___________ ?
| A．which you work | B．in which you work |
| C．for which you work | D．where you work in |