We know a lot about our world. When people are near a river or a sea, you feel cool. Why did the sun make the earth hot, but it can't make the water hot. Though the air over the earth becomes hot, the air over the water stays cool. The hot air over the earth goes up, then the cool air over the water moves in and takes the place of the hot air. When you are near a river or a sea, you feel the cool air when it moves in. You feel the wind and the wind makes you cool.
However, scientists can't answer all of the questions. If we ask "Why is the sea full of salt(盐)?" scientists will say that the salt comes from rocks. When a rock gets very hot or very cool, it cracks(破裂）, and rain falls into the cracks. The rain then carries the salt into the earth and the rivers. The rivers carry the salt into the sea. But then we ask "Why do not the seas get saltier?" scientists are not sure about the answer to the question. Scientists can explain many things, but not everything.
本时文内容由奇速英语国际教育研究院原创编写，未经书面授权，禁止复制和任何商业用途，版权所有，侵权必究！（投稿及合作联系：028-84400718 QQ：757722345）
13980503458
13980503458
admin@qisuen.cn
