首页| 英语软件下载| 设为首页| 加入收藏
英语词汇 |  英语阅读 |  留言反馈 |  免费英语软下载 |  论坛 |  英语作文 |  网络课堂 
英语词汇|家长课堂|英语阅读| 英语作文| 初中试题|听力特区 | 英语翻译| 英语词汇| 英语阅读| 听力口语| 英语文化| 趣味英语| 英语考级| 应用英语
出国英语: 雅思 剑7真题 托福 GRE 公共英语 考研英语 四六级 在职申硕 在职攻硕 英语充电 新概念 口语 语法 词汇
职业考试: 商务英语 口译 笔译 旅游饭店英语 多 语 种 标准日本语 日语等级 德语 法语 韩语 俄语 生存西班牙语 交际西班牙语  
全真题库: 英语四级 英语六级 考研英语 专业英语 自考英语 商务英语 职称英语 公共英语 新概念英语 中考英语 高考英语 翻译资格

台风是怎么形成的?

时间:2009-11-24来源:互联网 作者:未知                      [打印]

    A bit of rain and wind in summer can be nice. But bad storms are quite different.
    Some of the worst storms are typhoons(台风). Every year, about 80 typhoons hit different places around the world. The strongest ones are usually around the Pacific Ocean and the South China Sea. Most of them happen in July, August and September.
    Why? When lots of seawater gets hot in the summer sun, it evaporates(蒸发) into the air. This makes the air hotter, too. When the air gets warm enough, it starts to move higher up into the sky. Then, cooler air around it rushes in to fill the space that is left. Once the air gets warmer, it starts to move more quickly, making wind. The wind goes in circles, and it keeps moving higher in the sky. The warmer the air gets, the quicker the wind moves. And when the wind moves faster than 30 meters a second, a typhoon begins.
    A typhoon has two parts. One is called the “eye”. This is right in the middle of a typhoon and is calm. The eye of typhoon can be about 40 kilometers wide. In the eye, the wind does not move so fast, and there are not many clouds in the eye. The other part of a typhoon is the wall of clouds around the eye. This is where the strongest winds and hardest rains are.
    Typhoons are very dangerous. They blow away houses and cars. And they can also kill people! Typhoons’ hard rains are bad for farmers’ crops.