1.词语意义类型

该类题目主要考查词义与词形（同义词、反义词、多义词、形近词、音近词）的辨析。

例题1：As the BBC pointed out,the greater①in cancer transmission from mother to fetus had been how cancer cells that have slipped through the placental barrier could survive in the fetus without being killed by its immune system.The answer,in this case at least,lies in a second mutation of the cancer cells,which led to the②of the specific features that would have allowed the fetal immune system to detect the cells as foreign.As a result,no attack against the invaders was launched.（2015年全国医学博士统考）

①A．threat B．puzzle C．obstacle D．dilemma

②A．detection B．deletion C．amplification D．addition(https://www.daowen.com)

【分析】第①题答案为B。该句的大意为：这些脱离胎盘的细胞如何不被免疫系统杀死，这是个令人费解的事情。threat“威胁”，puzzle“疑团”，obstacle“障碍”，dilemma“进退两难”，根据句意，本题正确答案为B。解答考查词义的题，必须将句子含义理解透彻。

第②题答案为B。上面提出的puzzle的答案是癌细胞进行了第二次变异，使其能允许免疫系统将其检测为异质的特质消失殆尽。这里只能选择表示“消失，磨灭”含义的词，才能符合文意。因此deletion是正确答案。detection“检测”，amplification“放大”，addition“增加”。

例题2：For years,scientists have been warning us that the radiation from mobile phones is detrimental to our health,without actually having any evidence to back these ______up.（2014年全国医学博士统考）

A．devices B．risks C．phenomena D．claims

【分析】答案为B。文章首句告诉我们多年以来，科学家们一直都在警告我们手机辐射有害健康，但这一警告没有任何证据可以证明。device“设备”，risk“风险”，phenomenon“现象”，claim“说法，宣称”。back up的意思是“支持”，支持的对象应该为“说法”，因此本题正确答案为B。