Ⅲ.阅读理解
All the planets in the solar system travel around the sun.There are eight planets in
the solar system.Years ago,there were nine planets.Ever since Pluto(冥王星)was
demoted(使降级), we've had just eight planets.
Some scientists have studied the farthest reaches of our solar system.They believe
there might be another planet out there.They call it Planet Nine.What would Planet
Nine be like?Scientists believe it could be about three times larger and ten times heavier
than the Earth.
If Planet Nine is out there,why haven't we found it yet?Scientists are still search-
ing for it because it' s so far away.They believe it could take Planet Nine as long as
20,0 o0 years to make one trip around the Sun.Scientists also think Planet Nine could be
as much as 10,000 times darker than Pluto.
It is very difficult to search for such a dark planet in the whole solar system.Could
our solar system have a ninth planet?We hope to know the answer in the near r future.
1.From the first paragraph,we can know Pluto ______.
A.is called Planet Nine
B.was a planet years ago
C.travels around the earth
D.is in the centre of the solar system
2.Scientists think Planet Nine may be ______.
A.three times larger than the sun
B.out of the solar system
C.ten times heavier than the Earth
D.the farthest planet from Pluto
3.We haven't found Planet Nine yet because ______.
A.it's far and dark
B.it doesn't travel around the sun
C.it's large and heavy
D.it's 20,000 times darker than Pluto
4.Which of the following could be the best title for the passage?
A.Solar System
B.Dark Pluto
C.Planet Nine
D.Eight Planets

1-4 BCAC