题目内容
18．学生应当知道如何学习，否则你的压力就会大．Students should learnhow to study，or you'll feelstressed out．
分析 how，or，stressed．
解答 答案：how，or，stressed．第一个空需要表达出怎样，用疑问词how，构成疑问词+to do结构，作为learn的宾语，否则用or来连接两个句子，表示压力很大用stressed out作为表语，与feel构成系表结构，故答案是how，or，stressed．
点评 or用于连接两个并列的句子，表否定，表示"否则，要不然"的意思．如：Hurry up，or you'll be late．快点，否则你要迟到啦．
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13．Love will ________ last （延续）if we love the whole fine things around us．（ ）
| A． | seldom | B． | always | C． | never | D． | sometimes |
1．In common with many countries，Britain has serious environmental problems．In 1952，more than 4，000 people died in London because of the smog．The governmentintroduced new laws to stop smog from coal fires and factories and thesituation improved a lot．
Today，London is much cleaner but there is a new problem：smog from cars．In December 1991，there was very little wind in London and pollution increased a lot．As a result，about 160 people died from pollution in just four days．
Part of the problem is the new"out of town"shopping centers．In the past，people often walked to shops near their home or went by bus．Now，many people drive to the new shopping centers．As a result，the small shops have disappeared and more people have to travel to do their shopping．
Critics（评论员） say that Britain needs better and cheaper public transport．Transportin Britain is very expensive．An early morning train trip from Glasgowto London（about 600km） can cost about 100 pounds，for example．A short 15-minute bus trip can cost over 1.00 pound．
Many people are trying to reduce the use of cars in Britain．Some cities now have special bicycle paths and many people cycle to work．Some people also travel to work together in one car to reduce the pollution and the cost．
Today，London is much cleaner but there is a new problem：smog from cars．In December 1991，there was very little wind in London and pollution increased a lot．As a result，about 160 people died from pollution in just four days．
Part of the problem is the new"out of town"shopping centers．In the past，people often walked to shops near their home or went by bus．Now，many people drive to the new shopping centers．As a result，the small shops have disappeared and more people have to travel to do their shopping．
Critics（评论员） say that Britain needs better and cheaper public transport．Transportin Britain is very expensive．An early morning train trip from Glasgowto London（about 600km） can cost about 100 pounds，for example．A short 15-minute bus trip can cost over 1.00 pound．
Many people are trying to reduce the use of cars in Britain．Some cities now have special bicycle paths and many people cycle to work．Some people also travel to work together in one car to reduce the pollution and the cost．
| Environmental problems in （91）Britain | |||
| Time | Causes | Results | Solutions |
| In the past | Smog from coal （92）firesand factories． | （93）More than4，000 people died in 1952． | New laws were introduced． |
| Today | Smog caused by （94）cars． | About 160 people died in a few days in 1991． | ●Provide （95）betterand cheaper public transport． ●Build special paths for bicycles ●Travel to work together in one car． |