北京时间2003年10月29日14时，太阳风暴袭击地球，太阳日冕抛射出的大量带电粒子流击中地球磁场，不少地方出现了绚丽多彩的极光．读图：太阳外部结构示意图，回答下题．

   The best way of learning a language is using it. The best way of learning English is talking in English as much as possible. Sometimes you'll get your words mixed up(混合) and people will not understand you. Sometimes people will say things too quickly and you can' t understand them. But if you keep your sense of humor(幽默感)，you can always have a good laugh at the mistakes you make. Don't be unhappy if people seem to be laughing at your mistakes. It's better for people to laugh at your mistakes than to be angry with you，because they don't understand what you are saying. The most important thing for learning English is："Don't be afraid of making mistakes because everyone makes mistakes."