Choose the word or phrase that best completes the sentence.
One danger is in ______ radioactive wastes which are produced during nuclear reactions.
A.consisting of
B.getting rid of
C.making use of
D.taking care of

Choose the word or phrase that best completes the sentence.
We should develop such ______ sources of energy as solar energy and nuclear energy.
A.tradition
B.alternative
C.revolutionary
D.surprising

Choose the word or phrase that best completes the sentence.
It’s important for the developed countries to reduce energy ______ as much as possible.
A.exhaustion
B.destruction
C.consumption
D.waste

Choose the word or phrase that best completes the sentence.
Hydroelectric power is produced by the fall of water ______ in a dam.
A.trapping
B.trapped
C.to be trapped
D.that trapped

Choose the word or phrase that best completes the sentence.
A huge amount of solar energy ______ the earth's outer atmosphere.
A.reach
B.reaches
C.that reaches
D.is reached

Choose the word or phrase that best completes the sentence.
There are over 2,000 varieties of snake, ______ are harmless to humans.
A.mostly they
B.most of them
C.most of which
D.which most

Choose the word or phrase that best completes the sentence.
For many years people have wondered ______ exists elsewhere in the universe.
A.that life
B.life which
C.whether life
D.life as it

Choose the word whose underlined part is pronounced differently from those of the rest.
A.drum
B.jute
C.jump
D.plug

Choose the word whose underlined part is pronounced differently from those of the rest.
A.fast
B.screen
C.cleanse
D.scrub

I travel by bus only when I have no alternative.
A.I resort to travel by bus only when I had no alternative.
B.It's my only alternative to travel by bus.
C.Traveling by bus is my only alternative.
D.I travel by bus only as a last resort.