The Solar System is made up of all the planets that orbit the
Sun. In addition to the planets, the Solar System also 1) ... of
moons, comets, asteroids, minor planets, dust and gas.
Everything in the Solar System 2)... around the Sun. The Sun
3) ... around 98% of all the material in the Solar System. The
larger the object is, the more gravity it has. Because the Sun is
so large, its powerful gravity 4) ... all the objects in the Solar
System towards it. At the same time, these objects, which 5)...
very rapidly, try to fly away from the Sun into the emptiness
of outer space and the Sun 6) ... to pull them inward. So the
objects 7)... trapped half-way in between.
Scientists 8)... about the number of planets in the Solar System.
Some of them 9)... that there are nine planets: Mercury, Venus,
Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.
Others 10)... that Pluto can’t be considered as a planet, it is just
the largest member of a distinct population called the Kuiper
belt. There are a lot of other points the scientists 11) ... about
nowadays. Perhaps you’ll find the answers to these questions?


1) a) consist; b) consists; c) is consisting.
2) a) revolve; b) revolves; c) are revolving.
3) a) contain; b) contains; c) is containing.
4) a) attracts; b) is attracting; c) are attracting.
5) a) m oves; b) is m oving; c) are m oving.
6) a) try; b) is trying; c) are trying.
7) a) becom e; b) becom es; c) are becom ing.
8) a) still argue; b) still argues; c) are still arguing.
9) a) think; b) thinks; c) are thinking.
10) a) believe; b) is believing; c) are believing.
11) a) debate; b) is debating; c) are debating

1.b

2.a

3.b

4.a

5.c

6.a

7.c

8.c

9.a

10.a

11.c