Like many other animals, swallows(燕子) will fly south when the days turn c___1____ and the l____2____ from trees begin to fall. They travel many miles to find a warmer winter. This k___3____ of travel is called migration (迁徙).

Birds are animals that like to migrate a lot when it is cold. About 600 out of 9,000 kinds of birds do it. They leave in a____4____ and come back during the w____5____ spring months.

     Many b___6____ don’t like the cold. They need food, but plants die and insects (昆虫) hide in w____7____. So, they’ll only come home the next year, when there will be plenty of food for them to eat.

But the trip i____8___ often hard and not safe. Many birds fly in groups and make noises. Cranes (鹤) fly in groups l___9___ the letter V, or in a row. Others travel in pairs or a____10____.

1. ________   2.________    3.________    4.________    5.________

6. ________   7.________    8.________    9.________    10.________

       A few minutes ago, walking back from lunch, I started to cross the street when I heard the sound of a coin dropping. It wasn’t much but, as I turned, my eyes caught the heads of several other people turning too. A woman had dropped what seemed to be a dime（十美分硬币）.

       The sound of a coin dropping on the street catches everybody’s attention. Whatever the coin is, no one ignores（忽视）the sound of it. It got me thinking about sounds again.

       There are so many sounds that catch the most attention. People in New York City seldom turn to look when they hear the siren（警报）of a police car or an ambulance（救护车）.

       When I’m in New York, I’m a New Yorker. I don’t turn either. I hardly hear a siren there.

       At home in my little town in Connecticut, it’s different. The faraway high sound of a police car, an ambulance or a fire siren brings me to my feet if I’m sitting and brings me to the window if I’m in bed.

       It’s the quietest sounds that catch our attention most easily, not the loudest. In the middle of the night, I can hear water dropping a hundred yards away through three closed doors. I’ve been hearing little creaking（吱嘎）noises and sounds in the middle of the night for twenty-five years in our house. Why do I never hear those sounds in the daytime?

1. The sound of a coin dropping made people _______.

   A. think of money                                              B. shout aloud

   C. pay attention to it                                    D. look at each other

2. People in New York _______.

   A. are used to sirens                                    B. don’t hear loud noises

   C. are interested in sounds                           D. don’t care about quiet sounds

3. The writer _______.

   A. has a bad hearing                                    B. stays up late at night

   C. comes from a little town                         D. sleeps next to the window

4. The last paragraph（段落）tells us that _______.

   A. the writer thinks a lot at night                   B. water should be turned off at night

   C. the sounds at night make the writer afraid  D. the quietest sounds at night are easily heard