A good teacher must be able to hold his students’ attention ____ he reaches the end of the class.
| A．when | B．after | C．until | D．unless |
We have a high regard for Mr. Black because he always tries to ________ his principles.
| A．live up to | B．look forward to |
| C．catch up with | D．put up with |
To make it more convenient for people to visit Taiwan, several _____air services fromthe mainland have come into use.
| A．reliable | B．Permanent |
| C．regular | D．constant |
一You don’t go to that supermarket quite often, do you?
—No, I only go there ______because it’s too far away from my house.
| A．gradually | B．Temporarily |
| C．occasionally | D．briefly |
The girl arranged to have piano lessons at the training center with her sister ______ she would stay for an hour.
| A．where | B．which | C．who | D．what |
Dave nearly ran into a block when walking down the street with his mind ______ on the word puzzle.
| A．to fix | B．fixing | C．fixed | D．was fixed |