Did someone ring you an hour ago?' Martin said to Susan.
A.Martin asked Susan whether anyone rang her an hour ago.
B.Martin asked Susan if someone had rung her an hour before.
C.Martin asked Susan whether someone rang him an hour ago.
D.Martin asked Susan if anyone had rung her an hour before.

Choose the correct answer.
Don't throw aerosol into a fire. An aerosol .......... if you ................ it into a fire.
A.will be exploded/ throw
B.would explode/ threw
C.explodes/ will throw
D.can explode/ throw

Choose the correct answer.
Nora is using my car right now. If she................ it back in time, you're welcome to borrow it.
A.brought
B.would bring
C.will bring
D.brings

Choose the correct answer.
If energy ......................inexpensive and unlimited, many things in the world would be different.
A.is
B.was
C.had been
D.would be

Choose the correct answer.
If we .......................serious about pollution, we ...................... more money on research.
A.had been/ spent
B.were/ had spent
C.were/ would spend
D.are/ will spend

Choose the correct answer.
Sea water is salty. If the oceans.................of fresh water, there ............. plenty of water to irrigate all of the deserts in the world.
A.consisted/ would be
B.consisted/ were
C.would consist/ could be
D.consist/ will be

Around 150 B.C. the Greek astronomer Hipparchus developed a system to classify stars according to brightness.
A.record
B.shine
C.categorize
D.diversify

(37) .................
A.when
B.as
C.while
D.since

(39)...............
A.which
B.they
C.when
D.who

The best title for this passage is ……………
A.Sea Harvest
B.Sea Food
C.Man and the Sea
D.Technology for Exploiting the Sea