the sun rises in the east and sets in the west, which is caused by the rotation of the earth as you all know. but have you ever thought of the effect of the earths rotation on man and can you imagine what would happen if the earth stopped rotating?
the radius of the earth is about 6,370 kilometres. it takes the earth 24 hours to rotate once. objects on the earths equator move with the earth at a speed of 460 metres per second, and the air close to the earths surface turns at the same speed. if the earth stopped rotating suddenly, the air would keep flowing eastward at a speed of 460 metres per second. the wind would be fourteen times as powerful as a hurricane. at the same time sea water would rush eastward at a speed of several hundred metres per second, which might do damages much greater than a seaquake would do. obviously, men could hardly stand such a catastrophe.
even if such a catastrophe would not happen, there would be a great temperature difference on the two hemispheres of the earth, and the four seasons of the year would no longer occur because a day and a night would be as long as a whole year instead of 24 hours. all this would greatly affect the life of human beings, imals and plants and that would cause worse results than anything imaginable.
也就是将读过的书的中心思想、段落大意、内容要点及写作方法等等,以提纲挈领的方式写出来。
也就是将书中的精彩观点、新颖材料及警句等摘抄下来,以备将来选用。这种读书笔记是大量的。做摘抄笔记时,最好让每段摘录自成一段。后面还应写上摘自什么书,多少页,该书的作者是谁,出版者是谁,哪一年出版的,都应写在摘抄的后面,以备将来查验、核对。两段摘录之间留下较大空白,这样做一是使摘录的眉目清楚,二是留下空白便于将来翻阅、运用时可以作批记。
也就是阅读后,将自己的心得、、感想等写出来。也叫。
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