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Typhoon is a very big wind.It usually starts at s l in July, August and September.
How does a typhoon h 2 ? In summer. when the sun heats down on the sea, the water gets hot.
Then the hot water evaporates (v.蒸发) and goes up into the a 3 . This makes the air hotter. When
the air gets warm enough, it starts to move h 4 up into the sky, and starts to move quickly, making
wind. The wind goes in circles, and it keeps moving higher in the sky. And when the wind moves faster
than 30 meters a second, a typhoon begins.
Typhoons are very d 5 . When a typhoon happens, it usually causes (引起) strong winds and heavy rain. We should be careful when a typhoon is coming.
1. 2. 3. 4. 5.