Complete the face file. Use the comparative form of the words in brackets (Hoàn thành hồ sơ khuôn mặt. Sử dụng hình thức so sánh của các từ trong ngoặc)
Comets are made of ice and pieces of rock. Asteroids are made of rock and metal, and are (1. heavy).
Most asteroids are much (2. big) than most comets.
You can find asteroids: (3. close) to the sun than comets. If comets get too close to the sun, they melt. So you can only find comets much (4. far) from the sun, where it is (5. cold) and ice doesn't melt.
Comets are (6. bright) than asteroids because they have long, white tails.
Comets are (7. rare) than asteroids. There are hundreds of millions of asteroids in our solar system, but far (8. few) comets - only about 4,000. For this reason, asteroids are (9. dangerous), as one of them is (10. likely) to hit the Earth.
