9．
阅读短文，从每题所给的A、B、C和D四个选项中，选出最佳选项。
The seasons on Earth
The
Earth that we live on is moving all the time. The Earth turns around itself
once every 24 hours. This gives us day and night. The Earth also travels around
the Sun once every year. This gives us the four seasons. We have spring and summer
when our part of the Earth leans (倾斜) towards the Sun. We have autumn and winter when our
part of the Earth leans away from the Sun.
In
many places on Earth, there are four seasons in a year. But in some places
there are only two seasons. For example, near the North Pole (北极) there are only winter
and summer. The winter nights are long. For more than two months you can't see
the Sun, even at noon. The summer days are long. For more than two months the
Sun never sets, and there is no night. In the tropics (热带地区) there are also two seasons: a rainy season (wet season) and a dry
season.
