[单项选择]第一篇 The Northern Lights The sun is stormy and has it own kind of weather. It is so hot and active that even the Sun’s gravity cannot hold its atmosphere in check! Energy flows away from the Sun toward the Earth in a stream of electrified particles that move at speeds around a million miles per hour. These particles are called plasma, and the stream of plasma coming from the Sun is called the solar wind. The more active the Sun, the stronger the solar wind. The solar wind constantly streams toward the Earth, but don’t worry because a protective magnetic fields surrounds our planet. The same magnetic field that makes your compass point north also steers the particles from the Sun to the north and south poles. The charged particles become trapped in magnetic belts around the Earth. When a large blast of solar wind crashes into the Earth’s magnetic field first gets squeezed and then the magnetic field lines break and reco
A. Indifferent
B. Sarcastic
C. Sharp
D. Appreciative

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