At school, some students are active ________ some are shy, yet they can be good friends with one another．

A．while

B．although

C．so

D．as

New technologies have made ________ possible to turn out new products faster and at a lower cost．

A．that

B．this

C．one

D．it

I am moving to the countryside because the air there is much fresher than ________in the city．

A．that

B．it

C．one

D．this

Attention, please．The last plane to London ________ off at 9∶00 pm．

A．take

B．takes

C．took

D．has taken

It has been proved ________ eating vegetables in childhood helps to protect you against serious illness later．

A．if

B．because

C．when

D．that

Please remind me ________ you are going．I may be in time to you off．

A．where

B．when

C．how

D．what

The doctor almost lost hope, but the patient finally ________．

A．gave up

B．pulled through

C．gave in

D．got through

It was nice of Kathy to help us a lot．We wouldn't have completed the task ________．

A．however

B．otherwise

C．therefore

D．though

After the accident, Christopher sometimes felt sorry ________himself, but never thought ________committing suicide．

A．at, with

B．with, in

C．for, of

D．in, for

In some places women are expected to earn money________ men work at home and raise their children．

A．but

B．while

C．because

D．though