[問題]PP-test2 第9篇Q96 (reading)

[kool]

The closest a large asteroid has come to flying
by Earth occurred on March 22, 1989, when asteroid
1989 FC came within 430,000 miles of our planet.
Astronomers did not detect asteroid 1989 FC until it
was already moving away from Earth. Only then did
they notice a dramatic decrease in the asteroid's
motion against background stars. The astronomers
failed to notice the approach, which must have been
on a near-grazing trajectory, because it came from
the direction of the Sun. Also, the Moon was nearly
full, further hampering observations.
The asteroid was about half a mile wide,
and though a collision with Earth would have been
catastrophic, a fluke of orbital geometry might have
lessened the impact a little. The asteroid orbits the
Sun in the same direction and at almost the same
speed as Earth, completing a revolution in about
one year. Therefore, its approach was rather slow
compared to other celestial objects. However,
because of Earth's large size, the planet's
gravitational pull would have accelerated the asteroid
during its final approach. If a collision had occurred,
the asteroid would have produced a crater five to ten
miles wide.
Asteroid 1989 FC is one of only thirty similar
bodies that are capable of approaching Earth. In
addition, several hundred to one thousand or more
asteroids wider than one-third of a mile are capable
of crossing Earth's orbit for a close encounter. For
example, on December 8, 1992, a large asteroid called
Toutatis, which measured 2.5 miles long by
1.6 miles wide, flew within 2.2 million miles of Earth.
Not one of the close encounters had been
anticipated by astronomers. To avoid the danger
of an asteroid collision, the threatening body would first
have to be tracked by telescopes and radar
and its course plotted accurately so its orbit could be
determined precisely. If an asteroid were found to be
on a collision course with Earth, astronomers could
provide timely warnings. The rogue asteroid might
then be nudged out of its Earth-bound trajectory by
use of explosive devices.


96. Which of the following statements
about close encounters between
Earth and the asteroids mentioned
in the passage is true?

A. They were not predicted by astronomers.
B. They involved tiny asteroids.
C. They were hidden from view by sunlight.
D. They typically occur once every three years.

ANS: A

根據紅色的句子...C不是也對嗎...

[micki]

按照版規, reading請加註第N篇, 謝謝

[portia]

看起來只有１９８９ｆｃ這顆
是符合ｃ的選項

其他的ａｓｔｅｒｏｉｄｓ並不符合
而題目是問ｔｈｅｙ　並不是問１９８９ｆｃ這顆

[kool]

了解...感謝回答