The sudden of the headmaster gave the children who were talking loudly in the classroom a great surprise.
| A．entrance | B．entry | C．absence | D．trial |
You will be successful in the interview ____ you have confidence.
| A．before | B．once | C．until | D．though |
The field research will take Joan and Paul about five months; it will be a long
time ____ we meet them again.
| A．after | B．before | C．since | D．when |
1 won’t call you, ________ something unexpected happens.
| A．unless | B．whether | C．because | D．while |
The manager suggested an earlier date ____________ the meeting.
| A．on | B．for | C．about | D．with |
I _____ it as a basic principle of the company that suppliers of raw materials should be given a fair price for their products.
| A．make | B．look | C．take | D．think |