ADMICRO

Read the following passage and choose the best answer to each question. Write your answers in the space provided. 

Of all the weather events that occur around the world, lighting is the single most powerful and most frequent. Lightning strikes somewhere around the Earth 100 times each second. A typical lightning strike carries enough electricity to power a small town. In less than a second, a lightning strike heats the surrounding air to temperatures several times hotter than the surface of the sun. Obviously, lightning strikes are powerful. But how do they work?

A lightning strike is the last of the complex chain of events that happen inside a cloud. This chain of events starts when warm air rises in the clouds and cold airdrops. As the cold air and warm air pass each other, they carry millions of tiny drops of water and ice. When these passing water drops hit each other, they create electricity. Just like the batteries in your MP3 player, this electricity has a positive and a negative side. In the cloud, the negative side is at the bottom, and the positive side is at the top of the cloud. This makes the cloud electrically unbalanced. When the imbalance becomes too great, a streak of lightning forms, reconnecting the positive and negative parts of the cloud.

Lightning has two basic forms: cloud to cloud lightning and cloud to ground lightning. Cloud to cloud lightning occurs inside a cloud and never touches the ground. Sometimes called heat lightning, cloud to cloud lightning is most common in the late afternoon and evening, when temperatures begin to fall and there is more movement between hot and cold air inside a cloud. Cloud to ground lightning is far more dangerous. Cloud to ground lightning usually occurs during a thunderstorm. Many people think that cloud-to-ground lightning will hit the latest available object, but this is not always true. Cloud to ground lightning is very unpredictable and can even hit objects very low to the ground.

According to paragraph 2, the electrical charge in a cloud is created by

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