倘若地球停止轉動會怎樣呢？
【內容提示】
人所共知，太陽從東方升起從西方落下，這是由於地球的鏇轉造成的。但是，你是否想過地球鏇轉對人類的影響嗎？你能想像到如果地球停止轉動會發生什麼事情嗎？請用你所學的物理、化學、數學、地理、生物等自然科學知識作一分析，寫一篇文章。文章要用連鎖反應的方法展開，把它寫成一篇因果鏈型的說明文。
下列詞語可供參考：
1．rotation n．鏇轉2．rotate v．鏇轉 3．radius n．半徑；半徑距離4．hurricane n．颶風5．hemisphere n．半球
【作文示範】
What Would Happen If the Earth Stopped Rotating?
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 earth＇s 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 earth＇s equator move with the earth at a speed of 460 metres per second, and the air close to the earth＇s 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 seaquake①would do. Obviously, men could hardly stand such a catastrophe②.
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.
（選自1987年7月7日《上海學生英文報》）
【詞語解釋】
①seaquake [＇si:kweik]n．海震
②catastrophe[k+＇t$str+fi]n．大災難；災禍
【寫法指要】
本文是用兩個因果鏈來說明地球停止轉動會給人類帶來災難的。第一個因果鏈在第二段：如果地球停轉，風速就會加劇，海水的流動也會加速，造成大颶風或海嘯，颶風或海嘯會給人類帶來災難。第二個因果鏈在第三段：如果地球停止轉動，兩半球之間的溫差會加大，不再存在四季，白天和黑夜就不是24小時，而是一年，這樣就會影響到人類和動植物的生存。這種災難是無法想像的。