【英语时差8,16】闪电的形状
时间：2018-12-27 作者：英语课 分类：英语时差8，16
The Shape Of Lightning Bolts As a thundercloud moves through the air, a strong negative charge gathers near its base. Because opposite charges attract, this negative charge is anxious to combine with the positive charges in the ground. Eventually a lightning bolt forms to neutralize 1 these different charges. We might think that this bolt would want to jump in a straight line; that the electric charge would try to find the most direct route between thundercloud and ground. Why then are lightning bolts so jagged and irregular? The answer has to do with the complex way a lightning bolt forms. Although it looks like it forms all at once, a lightning bolt is actually produced in many steps. Instead of jumping right to the ground, the cloud’s negative charge begins with a short downward hop 2. This initial 3 hop is called a “leader,” and it’s no more than a few hundred feet long. From the lower end of this leader, another leader forms, and from the lower end of this, another. In this manner, the negative charge hops 4 downward from leader to leader like a frog jumping from lily pad to lily pad across a pond. While this is going on, the ground sends up its own chain of shorter, positively 5 charged leaders. It’s only when these two chains meet, about a hundred feet off the ground, that we see the lightning bolt’s flash. Lightning is jagged because each leader forms independently of the others. Each place a lightning bolt zigs or zags is where one leader stopped and another one started. Each place a lightning bolt forks is where two separate leaders formed from the bottom end of a single leader above. This whole process takes only a few thousandths of a second, but that’s enough time to sculpt 6 beautiful and complex lightning bolts.
- Nothing could neutralize its good effects.没有什么能抵消它所产生的好影响。
- Acids neutralize alkalis and vice versa.酸能使碱中和碱，亦能使酸中和。
- The children had a competition to see who could hop the fastest.孩子们举行比赛，看谁单足跳跃最快。
- How long can you hop on your right foot?你用右脚能跳多远？
- After she'd overcome her initial shyness,she became very friendly.她克服了起初的羞怯之后，变得十分友善。
- The experiments have given initial results eventually.那些试验总算初见成效了。
- The sparrow crossed the lawn in a series of hops. 那麻雀一蹦一跳地穿过草坪。
- It is brewed from malt and hops. 它用麦精和蛇麻草酿成。
- She was positively glowing with happiness.她满脸幸福。
- The weather was positively poisonous.这天气着实讨厌。