四、还原信息
Canada geese do not live only in Canada. They spend spring and summer in Alaska and northern Canada. (1)
E
They usually fly to northern Mexico, but lately many began to fly to the south of the USA. This may be because it is warmer there now than it was in the past.
Canada geese fly very fast. They can fly as fast as 100 kilometres per hour. The geese usually travel in groups of about 100, but groups of 1,000 are also common (常见的). (2)
D
But on sunny days they can fly as high as 2,500 metres.
Canada geese know when to travel. When the day becomes shorter and the temperature gets lower, they know it is time to leave. (3)
C
A few days before leaving, all the geese get very excited. The Canada geese make a “V” shape in the sky when they fly south. This makes it easier for them to fly through the air. Each goose takes a turn being the first goose. (4)
F
Some scientists think the geese use the stars at night to help them know where they are.
A. They do well in checking the instructions.
B. They fly to the east of the USA.
C. This is usually at the end of August.
D. On cloudy days, the geese fly lower.
E. In autumn, many of these geese move to warmer places.
F. No one is sure how the geese find their way.
