I.

1. Solar System 

2. comet 

3. galaxy 

4. soil 

5. satellite 

6. astronomers 

7. sand dunes 

8. telescope 

9. spaceships 

10. observatory 

II

1. shouldn't

2.might

3.mustn't

4.have to

5.has to

III. 

1.many differences

2.a force

3.pretty strong

4. of the American astronauts who visited the Moon

5.to float down slowly

6.the force of gravity

7. be moving freely

CHO MÌNH 5 SAO+CTLHN+CẢM ƠN NHÉ

I.

1. Solar System (Hệ Mặt Trời)

2. comet (sao chổi)

3. galaxy (dải ngân hà)

4. soil (đất)

5. satellite (vệ tinh)

6. astronomers (nhà thiên văn học)

7. sand dunes (đụn cát)

8. telescope (kính thiên văn)

9. spaceships (tàu ko gian)

10. observatory (đài thiên văn)

II.

1. shouldn't

2. might

3. must

4. have to

5.  has to

III.

1. differences

2. a force

3. pretty strong

4. astronauts

5. float down

6. force of gravity

7. be moving freely