[求助]OG11-67内那个But是干啥用的

67. Defense attorneys have occasionally argued that their clients' misconduct stemmed from a reaction to something ingested, but in attributing criminal
                    or delinquent behavior to some food allergy, the perpetrators are in effect told that they are not responsible for their actions.

(A)         in attributing criminal or delinquent behavior to some food allergy

(B)         if criminal or delinquent behavior is attributed to an allergy to some food

(C)        in attributing behavior that is criminal or delinquent to an allergy to some food

(D)        if some food allergy is attributed as the cause of criminal or delinquent behavior

(E)         in attributing a food allergy as the use of criminal or delinquent behavior

看了答案是B，可是对那个But的“转折”作用百思不得其解，请各位老师指教！

这个要从句子的意思来理解.

Defense attorneys have occasionally argued that their clients' misconduct stemmed from a reaction to something ingested, 其实是律师的一种狡辩, 说罪犯的不当行为是对其所食用东西的反应

but 后面是对前面句子意思的转折, 即作者对这种狡辩的反驳, but 后面句子的意思是, "如果将犯罪比作是食物过敏, 那么罪犯实质上被告知他们不用对自己的行为负责"

大概翻译了一下, 希望你能理解

Dear Dingxiang:

Thank you very much for your help.

还有一个问题请不吝赐教，此题正确答案中出现了IF DO，DO的句式。这种用法符合语法吗？是什么样的用法呢？我只知道IF DID，WOULD；和IF DO，WILL的用法呢。

未必if都是和虚拟语气有关吧。

何种语气应该从上下文来理解

这个问题我还真没有想到过,

我觉得你说的If的两种用法是当if 作条件从句时候的用法, 也就是两个动作一前一后用, 但此处其实两个动作是同时的, 所以都用一般现在时, 没有必要一个用将来时.

因为手头没有专门的语法书, 看了白勇,刘振民的语法, 好像也没有提到if的用法, 所以这样解释不知道你能接受伐.

今天正好在OG11 verbal review看到跟这句if用法一样的句子

95． If Dr． Wade was right, any apparent connection of the eating of highly processed foods and excelling at sports is purely coincidental．

(A)  If Dr．Wade was right，any apparent connection of the eating of

(B)  Should Dr．Wade be right，any apparent connection of eating

(C)  If Dr. Wade Is right, any connection that is apparent between eating of

(D)  If Dr．Wade is right，any apparent connection between eating

(E)   Should Dr．Wade have been right，any connection apparent between eating

答案是D此处也是if A do, B do.

楼主可以参考一下

这样的例子还很多呢, 又比如verbal review 的39题