VOA慢速英语:Tornado Season Returns

短语讲解：

1. Last Tuesday a series of storms tore across the Dallas-FortWorth area in Texas.

a series of 一系列
例句：He proposed a series of informal meetings. 
他建议举行一系列非正式会议。 

2. Reports say the storms killed at least thirty-nine people infive states.

at least 至少
例句：  At least, I sincerely hope so. 
至少我是真诚地这样希望的。

3. Because of their circular movement, these windstorms are alsoknown as twisters.

Because of　因为
例句：Because of their relative rarity, they are often missed. 
因为相对少见，它们常被漏诊。

4. But no matter what the size, tornado winds are the strongest onEarth.

no matter what 不管什么
例句：No matter what we do, we must carry out our duties. 
无论干什么工作,我们都应履行自己的职责. 

5. Yet tornadoes can be difficult to see.

be difficult to 很难
例句：The selection here is very large, it may be difficult to choose. 
这里有很多式样可以选，可能很难决定。

6. But tornadoes at night are usually impossible to see.

be impossible to 不能的.....
例句：He be so bigoted that it be impossible to argue with him 
他固执得不可理喻 

7. But they have been reported to move in other directions and asfast as one hundred seventeen kilometers an hour.

move in 迁入
例句：We have just moved in.
我们才刚搬进来。
as...as... 像...一样
例句：The body must dissipate heat as fast as it produces it. 
人体散发热量必须和产生热量一样快。

8. They are based on levels of damage to twenty-eight differentkinds of structures and other objects.

base on 把…建立在…的基础上
例句："Base on Yunfu, orient to the world and aim at the future." 
立足云浮,面向世界,走向未来。