用英文写一篇文章解释世界为什么有白天和黑夜

Night and day and night,are two different problems.Reflect the day and night the earth as an opaque ball,relative to the sun in the solar system backward relationship;Day and night change reflects the earth as a movement of the ball,in the process of sports being constantly adjust itself to the dorsal part of the sun.We think simply replace causes only comes down to the earth's rotation,day and night for geography teachers,especially the non-professional and full-time middle school geography teachers to study and grasp Gao Chuzhong about this part of the content of teaching material,has caused some difficulties.Therefore,it is necessary to discuss.Generally call day and night,it is to point to a day,24 hours 3 minutes and 56 seconds,often said to 24 hours.In more than one day,from day to night again by the reciprocating alternately,night into day is night
昼夜和昼夜更替,是两个不同的问题.昼夜反映的是地球作为一个不透明的球体,在太阳系中相对于太阳的背向关系；昼夜更替反映的是地球作为一个运动着的球体,在运动过程中不断调整着本身对于太阳的背向部位.我们认为简单地把昼夜更替成因只归结为地球自转,对于地理教师,尤其是非专业而专职的中学地理教师钻研和把握高初中有关这部分内容的教材,造成了一定的困难.因此,有必要进行探讨.
一般所说的昼夜,是指一个太阳日,即24小时3分56秒,通常说成24小时.在一个以上的太阳日中,由白昼到黑夜再由黑夜变成白昼的交替往复,就是昼夜更替.