The English physician Edward Jenner found that if experimental subjects were deliberately infected with cowpox, which caused only a mild illness, they are immune from smallpox.


which caused only a mild illness, they are immune from

causing only a mild illness, they become immune from

which causes only a mild illness, they are immune to

causing only a mild illness, they became immune from

which caused only a mild illness, they would become immune to

加入错题本 分享
纠错
考题讲解

题目分析：
略。

选项分析：

A选项：由于they are immune from smallpox是一个虚拟的情况，即，它是存在于“实验者感染cowpox”的情况下的，因此，其应该用虚拟语气，即，they would become immune from smallpox。

B选项：分词短语causing only a mild illness是伴随状语，其主语为它所修饰的句子的主语，即，experimental subjects。但在逻辑上，引起疾病的应该是 cowpox，而不是experimental subjects。

C选项：本选项错误同选项(A)。

D选项：本选项错误同选项(B)。

E选项：Correct. 本选项在语法和逻辑上均是正确的。

展开显示

登录 或 注册 后可以参加讨论

OG2018-SC