题目

我国南方地区经历了强降雨天气，尤其是广东、广西等省出现8到10级雷暴大风雨，这是强对流天气肆虐的结果。完成小题。 （1） 据材料可知，这次华南雷暴天气的降水类型主要是（ ） A . 梅雨 B . 锋面雨 C . 地形雨 D . 对流雨 （2） 强雷暴天气发生时，我们应尽量（ ） A . 站在露天，空旷的地方观赏 B . 在家上网或看电视 C . 躲藏在大树下或汽车里 D . 躲避在房屋等坚固绝缘掩体下Can you imagine astronauts' everyday life in space? They also need to eat,  sleep, exercise and relax. They do the same things as us, but they do them differently. On Earth, we put food on a plate. Gravity holds the food down and keeps it on a place. But there is almost no gravity in space, so food can float （漂浮）away, and astronauts must eat carefully. Sleeping is very different in space. Some astronauts like to float in the air, but most like to be in a sleeping bag. They tie the bag to a wall so that they won't float away at night. Exercise is very important in space. On Earth,  your legs carry your body,  but in space, astronauts float, so they do not use their legs often. This is very bad for their legs, so they must exercise for thirty minutes every day. After a day's work, astronauts relax. They may listen to music, read, watch films, play games, or talk to their friends and families on the radio. Sometimes they just enjoy floating in the air. 1.What does the underlined word "gravity" mean in Chinese? A．平衡 B．引力 C．磁性 D．重力 2.Why do astronauts tie the sleeping bag to a wall? A．Because in that way they won't float away. B．Because that makes them sleep well. C．Because they can't get to sleep if they don't do that. D．Because the sleeping bag is not safe enough. 3.What's the main idea of the passage? A．It is about the importance of gravity. B．It is about astronauts' everyday life in space. C．It is about the differences between space and Earth. D．It is about how to avoid （避免） floating away while sleeping.