GWD1-Q20

zcooles

In the mid-1970’s, since birds were overcome by pollution, and routinely falling from the sky above Los Angeles freeways, this prompted officials in California to devise a plan that reduced automobile emissions.

A.    since birds were overcome by pollution, and routinely falling from the sky above Los Angeles freeways,   this prompted officials in California to devise a plan that reduced
B.    since birds that had been overcome by pollution were routinely falling from the sky above Los Angeles freeways, it prompted officials in California to devise a plan that would reduce
C.    birds had been overcome by pollution and routinely fell from the sky above Los Angeles freeways, prompting officials in California to devise a plan that reduced
D.    birds overcome by pollution routinely fell from the sky above Los Angeles freeways, prompting officials in California to devise a plan to reduce
E.    birds overcome by pollution and routinely falling from the sky above Los Angeles freeways were prompting officials in California to devise a plan to reduce

答案是D
為什麼B不行?因為too wordy?

wangliming

At least two problems with B).

1. "had been", wrong verb tense. "In the mid-1970" suggests simple past tense.

2. "it" has no referent.

zcooles

謝謝NN的勞動
我當初是想had是表示發生在過去某事之前
所以我翻譯成以前可以克服廢氣的鳥現在會薰暈掉下來
這個概念不能用在這裡嗎?
B錯另一個原因是不是不該用be...ing?

wangliming

好意思，我对这些时态的中文单词搞不清楚，所以我用英文来说吧。

In generally, use simple past tense if possible. For instance, you will say,
"Yesterday, I found out that Dinosaurs lived on Earth for 3 million years" (sorry that I made up the number....)

Use past perfect tense ONLY if you need to emphasis the sequence of the action.
"Yesterday, I found out that Dinosaurs had lived on Earth for 3 million years before they died out."
Here, you wanna to emphasize the sequence of two actions, namely "had lived" and "died out."

In the absence of other better choices, you may use "had".