Last week，Chicago became the first city in the US to join the "Lights Out Plan"．People turned off the lights in the city's tallest buildings，so that thousands of birds could get to their winter homes．Every year in autumn，some birds fly over Chicago on their way to the south，and come back the next spring．

Lights mean danger to birds．Birds find their way by looking at the stars in the sky．Lights in tall buildings are so bright that birds may mistake them as stars．This means they can not find the right way to go home．

This month，about 300types of birds are flying over Chicago to go back to the south to live through the cold winter．Birds fly to warmer places for a few reasons．Many birds cannot live in the cold，so they fly to warmer places．But there are other reasons，too．Birds need to look for food in the south．Another reason is that they want to have baby birds．Many birds like to have their baby birds in the same "house" they lived in last year，so they fly back there．

There are about 9，000kinds of birds in the world，and about 600kinds of birds migrate（迁徙）．Some birds can fly a very long way．Sometimes they fly to other countries．We have fewer birds today because there are fewer places for birds．

64．Why did people in Chicago turn off their last week？　　

A．Because people wanted to save money．

B．Because people liked the dark night．

C．Because people were a afraid that birds would make much noise．

D．Because people were a afraid that birds would lose their way．

65．What does the underlined word "migrate" mean in Chinese？　　

A．迁徙

B．定居

C．冬眠

D．重生

66．Today we have fewer birds because　　．

A．lots of birds are often ill

B．people kill lots of birds

C．there are fewer places for birds

D．other animals eat them

67．Which of the following statements is NOT true？　　

A．All birds fly to warmer places every year．

B．Some birds have to fly to warmer places in autumn．

C．Some birds can fly a long way to other countries．

D．About 600kinds of birds migrate in the world．