The word“day”has two meanings. When we talk about the number of days in a year,
we are using“day”to mean 24 hours. But when we talk about day and night, we are
using“day”to mean the time between sunrise and sunset. Since the earth looks
like a ball, the sun can shine on only half of it at a time. Always one half of
the earth is having day and the other half night. A place is moved from day into
night and from night into day over and over by the spinning（旋转）of the earth. At
the equator（赤道）day and night are sometimes the same length（长度）. They are each
twelve hours long. The sun rises at 6 o’clock in the morning and sets at 6
o’clock in the evening. For six months the North Pole is tilted（倾斜）toward the
sun. In those months the Northern Hemisphere（半球）gets more hours of sunlight than
the Southern Hemisphere. Days are longer than nights. South of the equator
nights are longer than days. For the other six months the North Pole is tilted
away from the sun. Then the Southern Hemisphere gets more sunlight. Days are
longer than nights. North of the equator nights are longer than days. Winter is
the season of long nights. Summer is the season of long days.
day这个词有两种意思，当我们讨论一年的天数时，我们用这个词表示24小时。但当我们讨论白天和黑夜时，我们用这个词表示日出和日落间的时间。由于地球呈球形，太阳只能照射到地球的二分之一的区域因此地球总有一半是黑夜一半是白天，日出日落的产生是地球自转导致。在赤道昼夜平分，均为12小时，日出6点日落18点。有6个月北极向太阳倾向，这段时间内北半球日照更多，白天更长，黑夜更短。另外6个月反之。冬天日照少，夏天日照多。
we are using“day”to mean 24 hours. But when we talk about day and night, we are
using“day”to mean the time between sunrise and sunset. Since the earth looks
like a ball, the sun can shine on only half of it at a time. Always one half of
the earth is having day and the other half night. A place is moved from day into
night and from night into day over and over by the spinning（旋转）of the earth. At
the equator（赤道）day and night are sometimes the same length（长度）. They are each
twelve hours long. The sun rises at 6 o’clock in the morning and sets at 6
o’clock in the evening. For six months the North Pole is tilted（倾斜）toward the
sun. In those months the Northern Hemisphere（半球）gets more hours of sunlight than
the Southern Hemisphere. Days are longer than nights. South of the equator
nights are longer than days. For the other six months the North Pole is tilted
away from the sun. Then the Southern Hemisphere gets more sunlight. Days are
longer than nights. North of the equator nights are longer than days. Winter is
the season of long nights. Summer is the season of long days.
day这个词有两种意思，当我们讨论一年的天数时，我们用这个词表示24小时。但当我们讨论白天和黑夜时，我们用这个词表示日出和日落间的时间。由于地球呈球形，太阳只能照射到地球的二分之一的区域因此地球总有一半是黑夜一半是白天，日出日落的产生是地球自转导致。在赤道昼夜平分，均为12小时，日出6点日落18点。有6个月北极向太阳倾向，这段时间内北半球日照更多，白天更长，黑夜更短。另外6个月反之。冬天日照少，夏天日照多。
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第1个回答 2013-07-27
“天”有两层含义。当我们在谈论一年的天数，
我们使用的是“天”的意思是24个小时。但是，当我们谈论白天和黑夜，我们
使用“天”是指日出与日落之间的时间。由于地球看上去
像个球，太阳一次只能照到它的一半。总是有一半
地球是白天，另一半的夜晚。一个地方从一天到
晚上，从昨晚到今天，一遍又一遍的旋转（旋转）的地球。在
赤道（赤道）白天和黑夜有时同样的长度（长度）。他们每个人
十二小时。太阳升起的早晨六点在6集
点钟在傍晚。六个月的北极倾斜（倾斜）向
太阳。在这几个月北半球（半球）越来越多小时的阳光
南半球。白天比黑夜长。赤道以南的
夜长于天。另外的六个月，北极倾斜
远离太阳。那么南半球得到更多的阳光。天
比黑夜长。赤道以北夜长于天。冬天
夜长的季节。夏天是漫长的日子。
我们使用的是“天”的意思是24个小时。但是，当我们谈论白天和黑夜，我们
使用“天”是指日出与日落之间的时间。由于地球看上去
像个球，太阳一次只能照到它的一半。总是有一半
地球是白天，另一半的夜晚。一个地方从一天到
晚上，从昨晚到今天，一遍又一遍的旋转（旋转）的地球。在
赤道（赤道）白天和黑夜有时同样的长度（长度）。他们每个人
十二小时。太阳升起的早晨六点在6集
点钟在傍晚。六个月的北极倾斜（倾斜）向
太阳。在这几个月北半球（半球）越来越多小时的阳光
南半球。白天比黑夜长。赤道以南的
夜长于天。另外的六个月，北极倾斜
远离太阳。那么南半球得到更多的阳光。天
比黑夜长。赤道以北夜长于天。冬天
夜长的季节。夏天是漫长的日子。