When the telephone rang, I happened_____ a book.
| A．to be reading | B．to read | C．read | D．to have read |
This is a story completely_____ by him, so don’t rust him.
| A．discovered | B．invented | C．found | D．known |
I can guess you were in a hurry. You _your sweater inside out.
| A．had worn | B．wore | C．are wearing | D．were wearing |
Historical experience can ____ as a most important source of information.
| A．serve | B．use | C．regard | D．prove |
--Who is the old man talking with your teacher?
---I don’t know. I _ him before.
| A．was never seeing | B．had never seen | C．never saw | D．wouldn’t see |
The doctor thinks he will pull ___ now. His temperature has gone down.
| A．together | B．through | C．over | D．around |