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举一反三
【单选题】Passage One Gravity is a slippery beast. We don’t know how strong it is, how it works or how fast its effects move. But this year we made progress. October saw the most accurate measurem...
A.
Because it gives people so much trouble.
B.
Because it is much stronger than expected.
C.
Because no progress has been made about it.
D.
Because it remains largely unknown to people.
【单选题】活动星系核通常能产生强烈的电磁波辐射，它的能量来源主要是?
A.
星系的并合等相互作用
B.
外星人的生产活动，如燃烧煤炭
C.
大量恒星的核合成活动
D.
超大质量黑洞的吸积活动
【单选题】Passage One Gravity is a slippery beast. We don’t know how strong it is, how it works or how fast its effects move. But this year we made progress. October saw the most accurate measurem...
A.
Newton and Einstein had similar opinions on the speed of gravity
B.
the author of the passage is in favor of Einstein’s thought about the speed of gravity
C.
astronomers think that both Newton and Einstein were wrong on the speed of gravity
D.
Newton’s thought about the gravitational effect is out of date
【单选题】Gravity is a slippery beast. We don’t know how strong it is, how it works or how fast its effects move. But this year we made progress. October saw the most accurate measurement yet of Newton’s gravit...
A.
two things far apart might vibrate in unison
B.
the ripples in space-time are only imagined
C.
there exist gravitational waves
D.
abrupt, violent cosmic events lead to gravitational waves