Although medical science ________ control over several dangerous diseases, what worries us is that some of them are returning．

A．achieved

B．has achieved

C．will achieve

D．had achieved

－Each of the students working hard at their lessons ________ the book．

－So have I．

A．is reading

B．has read

C．read

D．reads

－Is Paul playing both soccer and tennis for the school?

－He ________．But now he has given up playing tennis．

A．is

B．has

C．was

D．had

－Well, you said you didn’t care very much for your job．________ you ________ giving it up?

－Not really．You see I have a lot of friends in the office．I’m part of the group．

A．Did; think of

B．Have; thought of

C．Had; thought of

D．Do; think of

－Have you ever worked with a tape recorder?

－I ________ it a lot when I was studying French in school．

A．used

B．was used

C．have used

D．had used

－Would you like another sandwich?

－Another sandwich?I ________ my first one yet．

A．hadn’t had

B．haven’t had

C．didn’t have

D．don’t have

I’m very disappointed with my neighbor．She said she would keep her cat off my grass, but she ________．

A．didn’t

B．hasn’t

C．wouldn’t

D．hadn’t

The unemployment rate in this district ________ from 6％ to 5％ in the past two years．

A．has fallen

B．had fallen

C．is falling

D．was falling

－Do you like traveling?

－Sure．I ________ to Australia six months ago, but I ________ anywhere since then．

A．went; didn’t go

B．have gone; haven’t gone

C．went; haven’t gone

D．went; hadn’t gone

Since 1999, the number of foreign students at German universities ________ from 113 000 to almost 200 000．

A．has increased

B．have increased

C．are increased

D．was increased