Bad habits, _________ formed, are difficult to get rid of.
| A．and | B．or | C．once | D．but |
Henry killed the dog. I'll ask him why ________.
| A．did he do that | B．he did that |
| C．he did | D．he has done so |
It worried her a bit ____ her hair was turning grey.
| A．while | B．that | C．if | D．for |
The reason why I didn't go to Shanghai was ________ a new job.
| A．because I got | B．because of getting |
| C．I got | D．that I got |
________ makes mistakes must correct them.
| A．What | B．That | C．Whoever | D．Whatever |
"Is Mary from New York City " "I don't know _______."
| A．from what city does she come from | B．from what city she come |
| C．what city does she come from | D．what city she comes from |