VOA慢速英语:Understanding How Tornadoes Work

短语讲解：

1. It extends from a thunderstorm in the sky down to the ground.

extend from…to… 从…延伸/扩展到….
例句：The country's trade extended from China to Europe.
该国的贸易从中国扩大到了欧洲。
in the sky 在天空中
例句：The stars twinkled in the sky.
天空星光闪烁。

2. A huge funnel cloud touches down in Orchard, Iowa, on June 10, 2008

touch down 降落，着陆
例句：The plane touched down at 17:45 at Heathrow Airport.
飞机于17点45分在希斯罗机场降落。

3. But no matter what the size, tornado winds are the strongest on Earth.

no matter what 无论什么，不管怎样，无论如何
例句：He's decided to leave tomorrow, no matter what.
不管发生什么事, 他已决定明天走。

4. On average, eight hundred tornadoes are reported nationwide each year.

on average 平均起来
例句：On average we receive five letters each day.
我们平均每天收到五封信。

5. During spring, warm air moves north and mixes with cold air remaining from winter.

mix with 与…混合
例句：You can mix this paint with water or oil.
你可用水或油调和这种颜料。
与…交往
例句：He did not easily mix with others. 
他不善于同他人相处。

6. The deadliest American tornado on record was the Tri-State Tornado of March eighteenth, nineteen twenty-five.

on record 有记载的，有记录的
例句：All the important events are on record.
重大事件都有记载。

7. But the outbreak of April third and fourth, nineteen seventy-four, set a national record.

set a record 创纪录
例句：She set a new world record for the high jump. 
她创下跳高的新世界纪录。
break a record 破纪录

8. Their work can be seen in the extreme weather videos that are increasingly popular on television and on the Internet.

extreme weather 极端天气
例句：Such extreme weather underscored the need to develop accurate long-range forecasts. 
这种极端的天气情况强化了发展准确的长期天气预报的需要。 

9. The goal of the project was to examine in detail how tornadoes are formed and the kinds of damage they cause.

in detail 详细地，详尽地
例句：She described the accident in detail.
她详细地叙述了那次事故。

10. For one thing, it is also bigger than most other countries. And it has many different conditions that create many different kinds of weather.

for one thing 一则，首先
例句：For one thing, you must work harder.
首先，你必须更加努力。