核心问题
____ the poem a second time, the meaning will become clearer to you.
A. Your having read B. While reading C. If reading D. When you read
有人说上题可以选 B, 理由是: While reading 可以解释为 While you are reading。
词典解答
上题只能选 D。因为主句的主语是 the meaning, 如果选 B, 则现在分词 reading 的逻辑主语就与句子的主语不一致了。while, when, if, though 等从属连词引导的从句虽然可以省略为 while/when/if/though + 分词, 但是有一个前提: 在一般情况下分词的逻辑主语必须与句子的主语相一致。