题目内容
14．Bad breath can be a major problem．The good news is that it can often be prevented with some simple steps．Bad breath is caused by certain bacteria that grow in the mouth．When you don't brush regularly，bacteria accumulate in your mouth and between your teeth．（36）ACertain foods，especially ones like garlic and onions that contain pungent （辛辣的）oils，can contribute to bad breath because the oils are carried to your lungs and out through your mouth．（37）CSome people think that as long as you brush your teeth，you shouldn't have bad breath．（38）EThat，however，just doesn't remove the smell．To sufficiently clean all the surfaces of your teeth，you should brush for at least 2minutes at least twice a day．
Many people believe that if you breathe into your hand，you'll know when you have bad breath．But it's wrong!（39）GWhen you talk，you tend to bring out the smell from the back of your mouth （where bad breath starts），which simply breathing doesn't do．Also，because we tend to get used to our own smells，it's hard for a person to tell if he or she has bad breath．
If you're concerned about bad breath，make sure you're taking care of your teeth and mouth properly．If you brush properly and visit your dentist for regular cleanings but your bad breath persists，you may have a medical problem．（40）BThey can figure out if something else is behind your bad breath and help you take care of it．
A．These bacteria make your breath smell．
B．In that case，call your doctor or dentist．
C．Smoking is also a major cause of bad breath．
D．Remember to brush your tongue，too-bacteria love to hang out there．
E．The truth is that most people only brush their teeth for 30to 45seconds．
F．When you breathe，the smell bounced back by your hand can be easily sensed．
G．When you breathe，you don^use your throat the same way you do when you talk．
分析 很多人都患有口臭，文章中分析了人们患口臭的具体原因．
解答 36-40．ACEGB
36 A 本段第一句Bad breath is caused by certain bacteria that grow in the mouth．公司我们口臭通常是由于口腔里的细菌导致的．积累在口腔里的细菌会让我们的口气很臭，故A项符合上下文串联．
37 C 本文正是解释导致口臭的几个原因，横线前句Certain foods，especially ones like garlic and onions that contain pungent （辛辣的）oils，can contribute to bad breath because the oils are carried to your lungs and out through your mouth．告诉我们大蒜和一些辛辣的食物会引起我们的口臭．本句也应该是告诉我们口臭的原因，故选C．吸烟也是口臭的一个主要原因．
38 E 根据本段最后一句To sufficiently clean all the surfaces of your teeth，you should brush for at least 2minutes at least twice a day．可知要想真正的清洁牙齿，我们每天至少要刷牙两次，一次至少2分钟，那么很多人口臭的原因就是刷牙时间不够，故选E．
39 G 根据后文When you talk，you tend to bring out the smell from the back of your mouth （where bad breath starts），which simply breathing doesn't do可知人们说话和人们呼吸时所使用的器官是不一样的，所以对着手吹起并不能判断出是否口臭，故选G．
40 B 根据前句If you brush properly and visit your dentist for regular cleanings but your bad breath persists，you may have a medical problem可知你经常刷牙，但仍然有口臭，这说明你可能有健康方面的问题，那你就要咨询医生，故选B．
点评 做七选五题目时要注意以下规则：1．放进去通顺，这一点是基础．凡不通顺的必错无疑； 2、选项中有单词、词组、句子成分或与所选答案所在段内容重合；3、选项与其上句或下句之间有必然的逻辑关系； 4、选项全部内容都属于正确答案所在段．有时备选答案中可能含有甲乙两项内容，这时，只有当甲和乙都归属于本段时，答案才是正确的．
