______ time went by , Herbert could finish all the maths exercises in class.
| A．With | B．As | C．while | D．Since |
Apples are usually sold by ________ weight and eggs are sometimes sold by ________ dozen.
| A．the; the | B．/;a | C．/; the | D．the; a |
Although punctual himself, the professor was quite used ________ late for his lecture.
| A．to have students | B．for students' being | C．for students to be | D．to students' being |
.When people move to another country, they often try ________ the customs of their native land.
| A．to keep on | B．to keep off | C．to keep up | D．keeping up |
The experiment is of particular importance.
—I see. We will carry on with it ________ we can get enough money.
| A．unless | B．though | C．whether | D．until |
.I think that this meal was well worth ________ was charged for it.
| A．that | B．what | C．which | D．how many |