When asked to explain ________ made his lessons so exciting, the teacher kept silent.
| A．what it was that | B．that what it was |
| C．what was it that | D．that what was it |
He has a part - time job and was paid___________.
| A．by the hour | B．by an hour | C．by hour | D．each hour |
The sunlight came in____________ the windows in the roof and lit up the whole room.
| A．through | B．across | C．by hour | D．each hour |
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 |