The stars are shining on a clear night. Suddenly you see some of them shooting across the sky.People say this makes you a very lucky person. Why? You have just seen a meteor shower!     How do meteor showers happen? When a comet goes around the sun, it gets very hot. Thiscauses small pieces of rock and ice to break off from the comet.     When the comet comes close to Earth, those small pieces get burned up in our atmosphere. It isa meteor shower, the fireworks of nature!     So how do you know when a meteor shower is coming? Luckily, scientists can often predictthem. And don’t worry about needing a telescope. You only need your own two eyes.     If you plan to watch a meteor shower, try to leave the city. A dark sky makes a meteor showerlook brighter.     Of course, the best place to watch a meteor shower is at the top of a hill. So bring along a warmblanket and hot drinks. Then just lie back and enjoy the wonderful show in the sky.

【題組】21. Where can we watch a meteor shower more clearly?
(A) On the top of a rock.
(B) In a big city.
(C) Under a dark sky.
(D) Inside a warm blanket.