－Did Jack come back early last night?

－Yes．It was not yet eight o’clock ________ he arrived home．

A．before

B．when

C．that

D．until

He went to a village ________ his grandfather once lived in．

A．where

B．when

C．that

D．until

Just after putting away the dishes ________．

A．the door bell rang loud

B．Nancy heard the doorbell ring

C．someone knocked at the door

D．the doorbell was rung

________ the poem a second time, the meaning will become clearer to you．

A．Your having read

B．While reading

C．If reading

D．When you read

The water will be further polluted unless some measures ________．

A．will be taken

B．are taken

C．were taken

D．had been taken

It was not until ________ that ________ to prepare his lessons．

A．did his father come in; the boy began

B．his father came in; the boy began

C．did his father come in; did the boy began

D．his father come in; did the boy began

________ is known to everybody, the moon travels round the earth once every month．

A．It

B．As

C．That

D．What

－I’m going to the post office．

－________ you’re there, can you get me some stamps?

A．As

B．While

C．Because

D．If

________ Chicago is a beautiful city today, but ________ Chicago of the 1920s was a very dirty place．

A．The; the

B．/;/

C．A; the

D．/; the

Doing your homework is a sure way to improve your test scores, and this is especially true ________ it comes to classroom tests．

A．when

B．since

C．before

D．after