为什么强风暴中具有双涡结构？
参考答案：
这是因为在有较强的垂直风切变环境中发展起来的风暴，从低层流入风暴的暖湿空气，它的流向与环境风方向相反，当热力上升气流与迎面的环境相对风相遇时，在风暴的中层便有双涡产生，即气流绕过风暴南边有利于造成气旋性旋转，气流绕过风暴北边有利于造成反气旋性旋转。在风暴中层发展起来的双涡，其旋转方向有助于把环境气流阻塞住，而低层气流由于同环境相对风的方向相反，双涡之间便将吸入更多的空气，能很有效的维持风暴内部的高速上升气流，从而风暴能维持而不受环境风的干扰。
| 完形填空。 Kelly Hall is 1 bank clerk, she works in a bank in town. She is 2 from morning to night. She gets up at six o'clock in the morning and 3 at half past six. After that she prepares (准备) breakfast. She has breakfast 4 the family at a quarter past seven. She goes to 5 at a quarter past eight. She finishes work at half past four and 6 home. She arrives home at a quarter to five. At half past six she makes dinner. Sometimes she watches TV __7__ an hour. On weekends, she often __8__ her son to the zoo. Her son likes the elephants. The elephants like 9 their friends. The little boy also likes koalas. They eat _10 _ at night. How interesting! | ||||
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