OG2020 SC769题 提问

弥敦道

OG2020 SC第769题
travelers from Earth to Mars would have to endure low levels of gravity for long periods of time, avoiding large doses of radiation, plus contending with the chemically reactive Martian soil, and perhaps even ward off contamination by Martian life-forms.
A. Mars would have to endure low levels of gravity for long periods of time, avoiding large doses of radiation, plus contending
B. Mars would have to endure low levels of gravity for long periods of time, avoid large doses of radiation, contend
C. Mars, having to endure low levels of gravity for long periods of time, would also have to avoid large doses of radiation, plus contending
D. Mars, having to endure low levels of gravity for long periods of time, avoid large doses of radiation, plus contend
E. Mars, who would have to endure low levels of gravity for long periods of time, avoid large doses of radiation, contend with

这道题OG给出的解释，是通过平行结构判定AC错误，通过缺少主句判定DE错误，虽然理解了，但CD选项中的having答案并没有提及，我想请问这里的having究竟是对是错，是什么语法结构，表达什么意思呢？

5Day

尝试着以C为例，代入整句分析。
Travelers from Earth to Mars, having to endure low levels of gravity for long periods of time, would also have to avoid large doses of radiation, plus contending
with the chemically reactive Martian soil, and perhaps even ward off contamination by Martian life-forms.

首先理解句意，粗略翻译，从地球到火星的旅行者，不得不忍受长时间低重力，避免大量射线，对抗化学性质活跃的火星土壤，还要隔离火星生物的污染。根据句意可以看出来是一系列动作（忍受、避免、对抗、隔离），根据平行原则，这些动词应该形式是一致的。

C貌似句意上也说得通，毕竟这些单词也都在，可惜时态不对。having to现在分词作状语，通常表达正在进行的动作。要注意的是，这里的动作本身是having to，而不是endure。我不确定“不得不”是否是一个可持续动词。另，这里是指一连串动作，而不是单个动作的持续。所以CD都不对。

一个更具迷惑性的答案可以是：Mars, having endured low levels of gravity for long periods of time, would also have to avoid large doses of radiation, plus contending
这时，having就不是动词了，而是表时态的助动词，动词时endure，这里的时态是完成时，表达已经忍受完了长时间的低重力，还不得不要避免……
但是同样的，这个答案可以根据句意或者平行性原则排除。

希望有帮助，共同交流。

弥敦道

5Day 发表于 2020-3-11 10:29
尝试着以C为例，代入整句分析。
Travelers from Earth to Mars, having to endure low levels of gravity f ...

感谢感谢，我以为这个帖子沉了就没管了，所以几天没上了

5Day

弥敦道 发表于 2020-3-16 02:23
感谢感谢，我以为这个帖子沉了就没管了，所以几天没上了

我每次上线都是挑最后发帖时间排序，然后挑0回复的帖子看。所以经常回挖坟帖哈哈哈