Theword"day"hastwomeanings．Whenwetalkaboutthenumberofdaysinayear，weareusing"day"tomean24hours．Butwhenwetalkaboutdayandnight，weareusing"day"tomeanthetimebetweensunriseandsunset．

Question

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 canshine on only half of it at a time．Always one half of the earth is having dayand the other half night．A place is moved from day into night and from nightinto day over and over by the spinning（旋转） of the earth．
At the equator day and night are sometimes the same length．They areeach twelve hours long．The sun rises at 6 o'clock in the morning and sets at 6o'clock in the evening．For six months the North Pole（北极） is tilted（倾斜） toward the sun．In those monthsthe Northern Hemisphere（半球） gets more hours of sunlight than the Southern Hemisphere．Days arelonger than nights．South of the equator nights are longer than days．For theother six months the North Pole is tilted away from the sun．Then the SouthernHemis phere gets more sunlight．Days are longer than nights．North of theequator nights are longer than days．Winter is the season of long nights．Summer is the season of long days．

81．When people talk aboutthe number of days in a year，the"day"here means___．
A．the timebetween sunrise and sunset          
B.12 hours
C.24 hours                     
D．from morning to evening
82．A place is moved from day into night and fromnight into day over and over by___ of the earth．
A．the pushing    
B．the pulling        
C．the spinning        
D．the passing
83．At the equator day is as long as night___．
A．sometimes          
B．never               
C．usually             
D．always
84．When the NorthPole is tilted toward the sun，the Northern Hemisphere gets___ sunlight．
A．less           
B．more        
C．all           
D．no
85．When it is winter in China，___．
 A．the USA is tilted toward the sun
 B．the South Pole is tilted away from the sun
 C．the North Pole is tilted toward the sun
 D．the North Pole is tilted away from the sun．

Answer 1

81：C．细节理解题，根据第一段When we talk about the number of days in a year，we are using"day"to mean 24 hours．可知指的是24小时，故选C．
82：C．细节理解题，根据第一段A place is moved from day into night and from night into day over and over by the spinning（旋转）of the earth．"理解可知．昼夜的交替是由地球的自转造成的．选C．
83：A．细节理解题，根据第二段"At the equator（赤道）day and night are sometimes the same length（长度）．They are each twelve hours long．"理解可知．赤道的昼夜长度有时是一致的．选A．
84：B．细节理解题，根据第二段"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．"理解可知．当北极点对向太阳时，北极地区获得的阳光要多些．选B．
85：D．细节理解题，根据第二段"For the other six months the North Pole is tilted away from the sun．Then the Southern Hemisphere gets more sunlight．"理解可知．当中国是冬天时，南半球倾向太阳光，北极点远离太阳，故选D．