TPO 18 Lightning - 英檢

最後一題挑文章重點

1. A storm cloud first develops a positively charged layer at the top then a
negatively charged middle layer and finally, a positively charged layer at the
bottom

2. Lightning from cloud to ground follows a channel that forms when a stream
of positive particles coming up from the ground

3. Lightning from a cloud to the ground is more likely to be destructive than
is lightning that takes place within a cloud

4. A separation of oppositely charged particles in clouds develops from
collisions of falling ice pellets with ice crystals, from updrafts and from
temperature variations

5. Field studies laboratory simulations and high-speed photography have all
been used to investigate the way charge separations develop in clouds

6. Once a channel has been formed it is usually used by several successive
electrical discharges that illuminate the channel as flashes of lightning.

想請問為什麼4.不對？

感覺上4.把第二段做了很好的摘要阿....

謝謝大家幫忙！

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