[思路分析]
b. no matter how
句子意思：
我们无论怎样解释吸烟对身体的害处,他都拒绝戒烟.
这里是由 no matter how 引导的让步状语从句.
这里后面的句子是完整的,不缺少成分,所以不用A.
有疑问可以给我发短信!
[解题过程]
■however的用法
1、however可以做副词,含义为“但是,可是,不过”.多插在句中,有时放在句首或句尾.
例如：However,they did not seem to have much effect.
不过,他们似乎没有起太大的作用.
He said that it was so;he was mistaken,however.
他说事情就是这样；然而,他错了.
由上文可以看出,第五单元的文章中的三句话中,however做副词,同学们可以试着翻译一下.
2、however还可以做连词,含义为“不管……如何,多么”,引导让步状语从句.从句的语序为：however+adj./adv.+主语+句子的其他成分.
例如：We shall never succeed,however much we try.
无论我们多么的努力,都不可能成功.
However cold it is,she always goes swimming.
无论天多冷,她总是去游泳.
注意：当however做连词时,可以转换为no matter how,因此上面的两个例句可以转换为：
We shall never succeed,no matter how much wetry.
No matter how cold it is,she always goes swimming.
从构词法的角度看,词尾加-ever的常用词还有：whoever,whomever,whosever,whatever,whichever,whenever,wherever等,这些词都可以引导让步状语从句,而且当它们引导让步状语从句时,可以转换为no matter who(what,when,where,which….).nomatter…是连词词组,做“不管”,“无论”解,no matter what(when,where,who)等的含义为“不管什么(何时,哪里,谁)”
例如：No matter who(=Whoever) knocks,don’t open the door.
不管是谁敲门,都不要开.
Nomatterwhat(=Whatever) happened,he would not say a word.
不管发生什么事,他总是一言不发.
I go to the theatre no matter when(=whenever) I get the chance.
每当我有机会,我就到剧院去.
No matter where(=Wherever) you work,you must write to me.
无论你在何处工作,一定要给我写信.
No matter whether you have time or not,you must deliver these clothes today.
不管你明天是否有时间,你必须今天把这些衣服送去.
在使用这些词的时候,同学们还需要注意下面的问题：
1、whatever,whichever,可以引导主语从句及宾语从句,此时不可以换成no matter…的形式.
例如：Whatever she did was right.(whatever引导主语从句,并在从句中做did的宾语).
她做的什么事都是正确的.
I will just say whatever comes into my mind.(whatever引导宾语从句,并在从句中做主语).我将只说我想到的.
She would tell him whatever news she got.(whatever引导宾语从句,并在从句中做定语).她会告诉他她得到的任何消息.
Whichever of you comes in first will receive a prize.
你们中先进来的人将得到奖赏.
I’ll take whichever (books) you don’t want.
我将拿走你不想要的任何书籍.
Take whichever seat you like.
坐你想坐的座位.
2、whoever,whomever与who,whom引导宾语从句及主语从句：
whomever是whoever的宾格形式.当whoever及whomever引导名词性从句时,相当于anyone who/whom.而who引导的名词性从句是由特殊疑问句演变而来.
whoever引导的名词性从句：
Whoever comes will be welcome.(Anyone who comes will be welcome.)
(whoever引导的是主语从句,whoever在从句中做主语)
所有来的人都将受到欢迎.
He knew the files could be of help to whoever took over the job.(He knew files could be help to anyone who took over the job.)
(whoever引导的是宾语从句,whoever在从句中做主语.)
他知道这些文件会对从事这项工作的人有帮助.
whomever引导的名词性从句：如果从句需要宾语,使用whomever,在口语中也可以使用whoever.例如：
Give it to whomever/whoeveryou like.
把它给你喜欢的任何人.
Whomever/Whoever you invite will be welcome.你邀请的人将受到欢迎.
who/whom引导的名词性从句：
I asked him who came into the room.
我问他谁进过这房间.
I asked him whom/whohesaw.
我问他他看见谁了.