题目内容
语篇理解
The most important diamonds are those we never see── the diamonds used in industry.Their value lies in their hardness, not their beauty, and in the thousands of jobs they do.
Industrial diamonds make the needles for phonographs(唱机).Diamonds cut through solid rock in search of oil.Doctors use diamonds too──often as a powder glued(粘) to paper or a wheel.Other diamond wheels cut and polish(磨光) stones and cut metal parts for all kinds of engines.They are also used to make wheels for grinding(磨碎) and polishing metals.
Most marvelous of all are the diamond dies(模具).These are flat diamonds through which small holes have been drilled(钻).When metal is pulled through the small hole in the diamond, it comes out as thin wire.
Cars, airplanes, nails, radios, refrigerators(电冰箱), and most electrical equipment could not be made without using industrial diamonds.
(1) The most important diamonds are those used ______.
[ ]
A.for jewelry
B.in industry
C.as drilling bits
D.both A and B
(2) The important quality in industrial diamonds is their ______.
[ ]
A.color B.hardness
C.beauty D.roughness(粗糙)
(3)A diamond die is a ______.
[ ]
A.thin wire
B.round, smooth diamond
C.diamond with a small hole
D.kind of drill
(4) The best title for this selection is ______. [ ]
A.Diamonds at Work
B.Man’s Best Friend
C.Diamond Dies
D.Grinding, Polishing and Cutting