Great as Newton was, many of his ideas

today and are being modified by the

work of scientists of our time.

A. are to challenge

B. may be challenged

С. have been challenged

D. are challenging

The second book was

by August 1952, but two years later, the end was still

nowhere in sight.

A. completed

B. to have completed

C. to complete

D. to have been completed

3/She ought to stop work; she has а headache because she

too long.

A. has been reading

B. is reading

C. has read

D. read

By the end of the year all but two people.

A. have left

B. will leave

C. will be leaving

D. will have left

It's reported that by the end of this month the output of cement in the factory

by

about 10%.

A. will have risen

B. has risen

C. will be rising

D. has been rising

My train arrives in New Y ork at eight o'clock tonight. The plane I would like to take fromthere

by then.

A. would leave

B. will have left

C. has left

D. had left

l May I speak to your manager Mr. Williams at five o'clock tonight?" I'm sorry. Mr.Williams

to a conference long before then.

A. will have gone

B. had gone

C. would have gone

D. has gone

We

our breakfast when an old man came to the door.

A. just have had

B. have just had

С. just had

D. had just had

9,/We

to start our own business, but we never had enough money.

A. have hoped

B. hope

C. had hoped

D. should hope

That tree looked as if it

for a long time.

A. hasn't watered

B. didn't water

С. hadn't been watered

D. wasn't watered

The gray building is where the workers live, and the white one is where the spare parts

A. are producing

В. are produced

13

C. produced

D. being produced