He began to ______because every means ______ tried already.
| A．lose heart; has been |
| B．lose heart; had been |
| C．lose his heart; was |
| D．lose his heart; had |
To understand the grammar of the sentence, you must break it ____ into parts.
| A．down | B．up | C．off | D．out |
The whole class________ the teacher attentively.
| A．are listening to | B．is listening to |
| C．are listening | D．is listening |
We don’t allow ____ in the office. But you are allowed ______ in the open air.
| A．smoking; smoking | B．to smoke; to smoke |
| C．smoking; to smoke | D．smoke; smoking |
What ____ fun it is to walk alone with ______ full moon hanging in the sky.
| A．/; a | B．a; / | C．the; / | D．a ;the |
All her time ________ experiments, she has no time to see films.
| A．devoted to do | B．devoted to doing |
| C．devoting to doing | D．is devoted to doing |