Measles, which once killed 450 children each year and disabled even more,was nearly wiped out in the United States 14 years ago by the universal use ofthe MMR vaccine. But thedisease is making a comeback, caused by a growing anti-vaccine movement andmisinformation that is spreading quickly. Already this year, 115 measles caseshave been reported in the USA, compared with 189 for all of last year.
麻疹, 曾一度每年导致450名儿童死亡，甚至更多的儿童致残，14年前由于MMR疫苗的普遍使用，在美国几乎被消灭。不过这种疾病正在卷土重来，这是因为不断增长的反疫苗运动和迅速传播的错误信息造成的。今年美国已经报告了115例麻疹病例，而去年全年为189例。
The numbers might sound small, but they are the leading edge of a dangerous trend. When vaccination rates are very high, as they still are in the nation as a whole, everyone is protected. This is called “herd immunity”, which protects the people who get hurt easily, including those who can’t be vaccinated for medical reasons, babies too young to get vaccinated and people on whom the vaccine doesn’t work.
数字听起来可能很小，但它们代表一种危险趋势。当全国范围内作为一个整体疫苗接种率很高时，每个人才会受到保护。这就是所谓的“群体免疫”，保护那些易受感染的人，包括那些因医疗原因不能接种疫苗的人，年龄太小不能接种疫苗的婴儿，以及那些疫苗不起作用的人。
But herd immunity works only when nearly the whole herd joins in. When some refuse vaccination and seek a free ride, immunity breaks down and everyone is in even bigger danger.
但群体免疫只有在几乎整个群体都加入时才起作用。当一些人拒绝接种疫苗并寻求自由乘车时，群体免疫就会崩溃，每个人都会面临更大的风险。
That’s exactly what is happening in small neighborhoods around the country from Orange County, California, where 22 measles cases were reported this month, to Brooklyn, N.Y., where a 17-year-old caused an outbreak last year.
从本月报告了22例麻疹病例的加利福尼亚州奥兰治县到去年一名17岁青年引发了一场麻疹疫情的纽约州布鲁克林，全国各地的小社区都是如此。
The resistance to vaccine has continued for decades, and it is driven by a real but very small risk. Those who refuse to take that risk selfishly make others suffer.
对疫苗的反对已经持续了几十年，因为存在真实但非常小的风险。那些拒绝冒险的人让别人承受痛苦，非常自私。
Making things worse are state laws that make it too easy to opt out of what are supposed to be required vaccines for all children entering kindergarten. Seventeen states allow parents to get an exemption, sometimes just by signing apaper saying they personally object to a vaccine.
更糟糕的是，州法律使得所有进入幼儿园的儿童放弃接种疫苗很容易。17个州允许父母选择放弃, 有时候，只需要签署一份声明，说他们个人反对疫苗。
Now, several states are moving to tighten laws by adding new regulations for opting out. But no one does enough to limit exemptions.
现在，有几个州正在加强法律，为退出接种增加新的规定。但没有人采取措施来限制放弃接种。
Parents ought to be able to opt out only for limited medical or religious reasons. But personal opinions? Not good enough. Everyone enjoys the life-saving benefits vaccines provide, but they’ll exist only as long as everyone shares in the risks.
父母应该只能因为有限的医疗或宗教原因选择放弃。但是个人意见呢？还不够充分。每个人都享受疫苗提供的拯救生命的好处，但只要每个人都分担风险，疫苗才会存在。
情态动词是每年高考的热点也是难点，每年单项填空题必考一题。考点集中在：情态动词表示推测的基本用法及区别;情态动词否定式的用法辨析：“情态动词+have done”的用法区别等。
虚拟语气在高考命题中不是重点，但是难点。考点常集中在含蓄条件句以及主语、宾语从句等特定句型中虚拟语气的使用上，因此考生应熟练掌握含蓄条件句中主从句的时态要求以及一些典型句型中虚拟语气的具体形式。
虚拟语气考点透析
考点一、虚拟语气的基本用法
1.与现在事实相反的虚拟语气，基本结构为：主语+动词的一般过去时(be动词用were)+其他成分+if+should/would/could...+动词原形+其他成分。例如：
①If it were not for the fact that she ______ sing，I would invite her to the party.
A.couldn’t B.shouldn’t C.can’t D.might not
解析 句意为：如果不是因为她不会唱歌的事实，我会邀请她来参加那次聚会的。that从句为同位语从句，描述的是事实，用陈述语气。正确答案为C。
2.与过去事实相反的虚拟语气，基本结构为：主语+动词的过去完成时+其他成分+if+should/would/could...+have done+其他成分。例如：
If the weather had been better，we could have had a picnic.But it ______ all day.
A.rained B.rains C.has rained D.is raining
解析 句意为：如果天气好的话，我们是能够去野餐的，但是下了一天的雨。句子前半部分陈述的是与过去事实相反的事情，所以用了虚拟语气。“下了一天的雨”是事实，所以用陈述语气。因为是发生在过去的事实，所以正确答案为A。
3.与将来事实相反的虚拟语气，基本结构为：主语+动词的一般过去时/should do/were to do+其他成分+if+should/would/could...+动词原形+其他成分。例如：
If I ______ plan to do anything I want to，I’d like to go to Tibet and travel through as much of it as possible.
A.would B.could C.had to D.ought to
解析 句意为：如果我能够计划做我想做的事情，我想去西藏并且尽可能多玩一些地方。句子描述的是与将来事实相反的事情，所以正确答案为B。
考点二、含蓄虚拟条件句
这样的虚拟句不含有if从句，而是以but for/without/or/otherwise等引导的句子代替if从句，主句的谓语动词的形式与前面虚拟语气的基本用法相同。例如：
Thank you for all your hard work last week.I don’t think we ______ it without you.
A.can manage B.could have managed
C.could managed D.can have managed
解析 由语境可知这里要表达的意思是：如果没有你们辛勤的工作，我们不可能处理好这件事。很显然，这是对过去发生的事实的虚拟，所以要用could have done，故应选B。
考点三、主从句时间不一致的虚拟条件句
在有些虚拟条件句中，主从句时间不一致，应根据不同情况区别对待。例如：
It’s hard for me to imagine what I would be doing today if I ______ in love，at the age of seven，with the Melinda Cox Library in my hometown.
A.wouldn’t have fallen B.had not fallen
C.should fall D.were to fall
解析 句意为：如果不是我在七岁时爱上家乡的Melinda Cox图书馆的话，很难想象今天的我会是什么样子。主句描述的是与现在事实相反的事情，从句描述的是与过去事实相反的事情。正确答案为B。
考点四、名词性从句中的虚拟语气
在含有表示坚持、建议、命令、要求等含义的名词性从句和在it做形式宾语或形式主语的复合句中，宾语补足语是necessary/strange/essential/natural/a pity/a shame等表示“惊奇、惋惜或者理应如此”等含义时，从句中的谓语动词需用“should+动词原形”，其中should可以省略。例如：
—Don’t you think it necessary that he ______ to Miami but to New York?
—I agree，but the problem is ______ he has refused to.
A.will not be sent;that B.not be sent;that
C.should not be sent;what D.should not send;what
解析 问句句意为：难道你不认为必须把他送到迈阿密而不是纽约吗?句子表示理应如此的意思。正确答案为B。
情态动词考点透析
考点一、情态动词基本含义的考查
情态动词的基本含义，一直是高考考查的重要内容。例如：
1. The fire spread through the hotel very quickly but everyone______get out. A. had to B. would C. was able to D. could
解析：考查情态动词的基本含义。had to：不得不; would：表示意愿或过去常常;could倾向于表示经过长期训练而获得的能力;was able to 表示经过努力而能够做到的事或成功地做了某事。因此，答案是C。
分析：高考对情态动词基本含义的考查，仍然集中在常用的情态动词上。对常用情态动词的含义，要掌握的既准确又要全面，特别是shall, should, can, may 四个常用情态动词的含义较多，不易理解，复习时应当引起重视。
二、情态动词表示推测的考查
对情态动词表示推测的用法，是高考考查情态动词的一个重要方面。例如：
1. Sorry, I’m late. I______have turned off the alarm clock and gone back to sleep again .
A. might B. should C. can D. will
解析：might have done : (过去)可能做过某事;shouldhave done :本应该做某事。根据本句提供的情境I’m late 表明说话人可能把闹钟关上了。答案是：A。
分析：高考对表示推测的情态动词集中在must, can, could, may, might上，准确掌握它们使用的场合，是解决问题的关键。Must 用于肯定陈述句，表示肯定推测;can, could用于疑问或否定陈述句，表示可能性推测;may, might用于陈述句，表示可能性推测;用于否定陈述句中，can’t (不可能)的语气比may not(可能不)强。此外，还要注意有对过去和对现在两种情况的推测,对过去推测用情态动词+have done ，对现在推测用情态动词+ 动词原形。
三、情态动词表示虚拟的考查
情态动词+have+过去分词表示与过去事实上相反的情况，也是高考单项选择题涉及到情态动词的一个重要方面。
1. There was a lot of fun at yesterday’s party. You______come, but why didn’t you?
A. must have B. should
C. need have D. ought to have
解析：ought to have done 表示本来应该做某事而实际没做，should do 表示现在应该做某事，与题中 at yesterday’s party 表示的时间不一致。所以选D。
分析：高考对情态动词表示虚拟‘用法，表示与过去事实相反的情况。近几年高考，主要侧重should (not)have done 这一句式上，表示本来不该做却做了或本来该做却未做的事，在复习时，还应关注其它几种虚拟形式，如need (not)have done 表示本来需要做而未做或本来不需要而做的事等等，以做到有备无患。
考点四、情态动词与助动词混合考查
1.Tom ,you didn’t come to the party last night?
—I______, but I suddenly remembered I had homework to do .
A. had to B. didn’t C. was going to D. wouldn’t
解析：had to:不得不;didn’t:没来;was going to：打算来;wouldn’t:不愿来。句意：——汤姆，昨晚你没来参加舞会吗?——我本打算来，但我突然记起有作业要做。But是关键词，所以答案是：C。
2.Your phone number again? I______quite catch it .
—It’s 86184867.
A. didn’t B. couldn’t C. don’t D. can’t
解析：记住电话号码并非难事，未完全听清楚电话号码并非能力的事，此处只是说没有完全听清楚电话号码，所以，应选A。
精选试题 模拟题及其答案
1. “I still haven’t thanked Aunt Lucy for her present.” “It’s time you _____.”
A. do B. did C. had D. would
2. If I hadn’t been lucky enough to meet you. I really _____ what I would have done.
A. don’t know B. hadn’t known
C. wasn’t knowing D. wouldn’t know
3. “I’ve told everyone about it.” “Oh, I’d rather you _____.”
A. don’t B. hadn’t
C. couldn’t D. wouldn’t
4. It has been raining for a day, but eventhough it hadn’t rained, we _____ there by tomorrow.
A. can’t get B. won’t get
C. hadn’t got D. wouldn’t get
5. “Do you know his address?” “No, I also wish I _____ where he _____.”
A. knew, live B. knew, lives
C. know, lives D. know, lived
6. “Isn’t it about time you _____ to do morning exercises?” “Yes, it is. Would you like to join us?”
A. begin B. have begun
C. began D. had begun
7. It is hard for me to imagine what I would be doing today if I ____ in love, at the age of seven, with the Melinda Cox Library in my hometown.
A. wouldn’t have fallen B. had not fallen
C. should fall D. were to fall
8. He hesitated for a moment before kicking the ball, otherwise he ____ a goal.
A. had scored B. scored
C. would score D. would have scored
9. If only he _______ quietly as the doctor instructed, he would not suffer so much now.
A. lies B. lay
C. had lain D. should lie
10. Without the air to hold some of the sun’sheat, the earth at night ____ for us to live.
A. would be freezing cold B. will be freezing coldly
C. would be frozen cold D. can freeze coldly
11. I forget where I read the article, or I _____ it to you now. w.w.w.k.s.5.u.c.o.m
A. will show B. would show C. am going to show D. am showing
12. “It looks as if he were drunk.” “So it does. _____.”
A. He’d better give up drinking
B. He shouldn’t have drunk so much
C. Health is more important than drink
D. I wonder why he is always doing so
13. “Mary looks hot and dry” “So _____ you if you had so high a fever.”
A. do B. are C. will D. would
14. “He will come tomorrow.” “But I’d rather he _____ the day after tomorrow.”
A. will come B. is coming
C. came D. had come
15. All the doctors in the hospital insisted that he ____ badly wounded and that he ____ at once.
A. should be; be operated on
B. were; must be operated on
C. was; should be operated
D. was; be operated on
16. ______ smoking, he would not have got cancer in the lung.
A. Was he given up B. Had he given up w.w.w.k.s.5.u.c.o.m
C. Did he give D. If he gave up
17. “I still haven’t thanked Aunt Lucy for her present.” “It’s time you _____.”
A. do B. did C. had D. would
18. “Do you know his address?” “No, I also wish I _____ where he _____.”
A. knew, live B. knew, lives w.w.w.k.s.5.u.c.o.m
C. know, lives D. know, lived
19. It is hard for me to imagine what I would be doing today if I ____ in love, at the age of seven, with the Melinda Cox Library in my hometown. w.w.w.k.s.5.u.c.o.m
A. wouldn’t have fallen B. had not fallen
C. should fall D. were to fall
20. Without the air to hold some of the sun’s heat, the earth at night ____ for us to live.
A. would be freezing cold B. will be freezing coldly
C. would be frozen cold D. can freeze coldly
21.________ fired, your health care and other benefits will not be immediately cut off.
A. Would you be B. Should you be
C. Could you be D. Might you be
22.You can’t imagine that a well-behaved gentleman _____ be so rude to a lady.
A. might B. need C. should D. would
23.—Excuse me. But I want to use your computer to type a report.
—You _____have my computer if you don’t take care of it .
A. shan’t B. might not C. needn’t D. shouldn’t
24. He _____ have completed his work; otherwise, he wouldn’t be enjoying himself by the seaside.
A. should B. must C. wouldn’t D. can’t
25. I ______ have been more than six years old when the accident happened.
A. shouldn’t B. couldn’t C. mustn’t D. needn’t
26. There _____ be any difficulty about passing the road test since you have practiced a lot in the driving school.
A. mustn’t B. shan’t C. shouldn’t D. needn’t
27. I was on the highway when this car went past fol. Lowed by a police car. They ______ at least 150 kilometers an hour.
A. should have been doing B. must have been doing
C. could have done D. would have done
28. — I’ve taken someone else’s green sweater by mistake.
— It ______ Harry’s. He always wears green.
A. has to be B. will be C. mustn’t be D. could be
29. — Catherine, I have cleaned the room for you.
— Thanks. You ______ it. I could manage it myself.
A. needn’t do B. needn’t have done
C. mustn’t do D. shouldn’t have done
30. — Lucy doesn’t mind lending you her dictionary.
— She _______. I’ve already borrowed one.
A. can’t B. mustn’t C. needn’t D. shouldn’t
答案与解析
1.
解析选B.It’s time you did 为 It’s time you thanked Aunt Lucy for her present 之略。按照英语语法，it’s time 后从句通常要用过去式。
2.
解析选A.虽然前有虚拟条件句, 后有使用了虚拟语气的宾语，但 I don’t know 却宜用一般现在时，因为 I don’t know 表述的是现在的真实情况，句意为“我要不是有幸遇到你，我真不知(指现在不知)我会做出什么蠢事来”。
3.
解析选B.I’d rather 后接从句时，从句谓语的时态规律是：用过去式表示现在或将来，用过去完成式表示过去。
4.
解析选A.we can’t get there by tomorrow 为客观事实，故宜用陈述语气。
5.
解析选B.第一空填 knew，因为 I wish 后的宾语从句要用虚拟语气(即用过去式表示现在的想法);第二空要填lives，即用陈述语气，因为 where he lives 是一个客观事实，而不是 I wish 的内容。
6.
解析选C.It’s time… / It’s high time… / It’s about time… 等后接从句时，从句谓语通常用过去式。
7.
解析选 B.此题涉及错综时间虚拟条件句，主句与现在事实相反，条件句与过去事实相反。句意为：要不是在七岁时就迷上了 Melinda Cox 图书馆，我真不能想像我如今会在做什么。
8.
解析8. 选 D.这是otherwise 引出的含蓄虚拟语气，再根据前面的 hesitated 可进一步知道这是与过去事实相反的虚拟语气，由此可推知答案选 D.
9.
解析选 C.if only意为“要是……就好了”，其后的句子谓语要用虚拟语气，同时根据 as the doctor instructed 中的过去时态可知从句是与过去事实相反，故选 C.
10.
解析选 A.without 引出的介词短语为一个与现在事实相反的含蓄条件句。
答案C
11.
解析.根据上文的语境可知句中的 or 隐含有一个虚拟的条件，即 or=if I didn’t forget where I read the article(要是我没忘记我在哪儿读过这篇文章的话——但事实上忘了)。
答案B
12.
解析关键信息是It looks as if he were drunk 中的虚拟语气，句子既然用了虚拟语气，也就是说，“他喝醉了”不是事实，只是他的言行好像是醉了，所以此题的答案是D.
答案 D.
13.
解析 由于空格后的 if 条件状语从句的谓语用的是虚拟语气(这是很重要的信息)，所以主句要用 would 而不用 will，即答案应选D.
答案D
14.
解析按照英语习惯，would rather 后接that 从句时，从句谓语通常要用虚拟语气，即用过去式表示现在或将来， 用过去完成时表示过去。
答案C
15.
解析insist后的从句谓语有时用“should+动词原形”这样的虚拟语气，有时不用，具体要看该谓语动词所表示的含义。一般说来，若该谓语动词所表示的动作尚未发生，或尚未成为事实，则用虚拟语气;若该谓语动词所表示的动作已经发生，或已经成为事实，则要用陈述语气。分析上题的句意，可知只有选D最合适。
答案D
16.
解析是因为时态前后有矛盾。由于主句谓语是would not have got，这表明是对过去事实作出的假设，所以从句谓语应该是 had given up，而不是像D项那样用一般过去时。另外，当虚拟条件句中有 had, should, were 等词时，通常可以省略 if，并将 had, should, were 提前置于句首。
答案B
17.
解析It’s time you did 为 It’s time you thanked Aunt Lucy for her present 之略。按照英语语法，it’s time 后从句通常要用过去式。
答案B
18.
解析第一空填 knew，因为 I wish 后的宾语从句要用虚拟语气(即用过去式表示现在的想法);第二空要填lives，即用陈述语气，因为 where he lives 是一个客观事实，而不是 I wish 的内容。
答案B
19.
解析 此题涉及错综时间虚拟条件句，主句与现在事实相反，条件句与过去事实相反。句意为：要不是在七岁时就迷上了 Melinda Cox 图书馆，我真不能想像我如今会在做什么。
答案B
20.
解析without 引出的介词短语为一个与现在事实相反的含蓄条件句。
答案A
21.
解析句意：万一你被解雇，给你的医疗救助和其它方面的福利也不会被取消。
答案B
22.
解析句意：你想象不到这么一个表现良好的绅士竟然会对一个女士这么粗鲁。
答案C
23.
解析shall此处表示“警告”。
答案A
24.
解析B此处考查情态动词表示推测的用法。should have done表示过去应该做而实际并没有做，因此淘汰A项。would不用来表推测，因此淘汰C项。B基与D项虽然都可以表示推测，但B项表肯定意义而D项表示否定推测，意为“不可能”，根据句意：他肯定已完成了他的工作;不然，他就不会在海边玩得那么愉快了。可知此处需要肯定意义，因此淘汰D项。
25.
解析B本题考查情态动词的用法。must表示推测只能用于肯定句，否定句用can或could 代替。shouldn’t have done 表示“本来不该而实际上却做了某事”.needn’t have done表示“本来不必而实际上却做了”均不合题意。本句的意思是：当事故发生时我不可能超过6岁。
26.
解析C should(按道理)应该;句意：既然你在驾校时做了大量练习，那么通过这次考试理不应该有困难。
27.
解析B 第一句话使用了一般过去时，由此可知第二句话是对过去事情的猜测，需用must have done.本题意为“我正在高速公路上行驶，这时一辆警车跟随着着这辆车从旁边经过。它们一定是以至少每小时150公里的速度行驶。”故选B。A项表示“本应该……”，C项表示“本能够……”不合题意。
28.
解析D 本题考查情态动词的用法。句意是“我错拿了别人的绿色 毛衣”，“那可能是Harry的，他总是穿绿色的毛衣”。四个选项中could表示推测。mustn’t 表示 “禁止”;has to 表示“不得不”;will 表推测时，表“肯定“语气太强。
29.
解析B根据句意可知Catherine对对方为她打扫了房间表示感谢并提到对方本来不必为她打扫房间。很显然对方打扫房间是过去所为，表达“去不必做某事”用needn’t have done sth.
30.
解析C本题考查情态动词，从答语的后半句“我已经借到一本字典了”，可知前半句为“不必了”。故C正确。