31. -----What do you suppose made her worried?
-----_____________ a gold ring.
| A．Because of losing | B．Losing | C．Lose | D．Lost |
Although no one wanted to talk about it, a terrible accident happen the other day.
| A．does | B．did | C．has to | D．had to |
When the fire fighters heard a ladyfor help in the burning house, they rushed into save her.
| A．to ask | B．asked | C．crying | D．to cry |
Cats are similar _______ tigers _______ several ways.
| A．with; to | B．to; in | C．in; to | D．on; with |
The pen I _______ I _______is on my desk, right under my nose.
| A．think; lost | B．thought; had lost | C．think; had lost | D．thought; have lost |
– Why does she look so tired?
-- She ________ all the morning and she still hasn’t finished it.
| A．cleaned | B．was cleaning | C．has been cleaning | D．has cleaned |