In his book,he explains both ______ it means to be a scientist and ______ science works.
| A．how; how | B．what; that |
| C．what; how | D．how; that |
Don’t ______ to spring-clean the whole house just because my mother is coming---there's no need to do that.
| A．undertake | B．attempt | C．bother | D．hesitate |
In order to get ________ better job of the two, he claimed that he could speak ________ second language, hoping it was an advantage over the other applicants.
| A．the; a | B．a; a | C．the; the | D．a; the |
He _______ English for four years before he went abroad.
| A．has studied | B．was studying |
| C．has been studying | D．had been studying |
Carelessness always contributes _______ car accidents. Therefore, drivers are advised to concentrate their attention _______ driving.
| A．for; to | B．to; on | C．with; on | D．in; to |
With a lot of difficulties _______, they went to the seashore and had a good rest.
| A．settled | B．settling | C．to settle | D．being settled |