The people lived in several cabins, each of which had a trapdoor.

人们住在几个小木屋里，每个小木屋都有一扇活板门。

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The dog was a stray which had been adopted.

这只狗是被收养的流浪狗。

《柯林斯英汉双解大词典》

The aquifer which had once fed the wells was pronounced dry.

曾经给这些井提供水源的蓄水层已被宣告枯竭。

《柯林斯英汉双解大词典》

And it had put to rest the great problem of slavery, which had troubled the nation for so many years.

VOA: special.2010.01.14

We saw that the Bohr model was able to correlate the observations of Angstrom, which had been formulated by Balmer.

知道了波尔模型,可以和阿姆斯特朗的观察相吻合，这观察后来被巴尔末推导出来相证实。

麻省理工公开课 - 固态化学导论课程节选

Archaeologists in the nineteenth and twentieth centuries were stunned to find the ruins and the records of remarkable peoples and cultures--massive, complex empires in some cases, but some of which had completely disappeared from human memory.

十九和二十世纪的考古学家们,震惊地发现了,古代伟大名族和文化的遗迹，有些还是大规模，复杂的帝国遗迹,但也有一些就完全从人类记忆中消失了。

耶鲁公开课 - 旧约导论课程节选

Money, which had really not featured in the British demarcation of social class, became very important.

BBC: Class calculator: A US view of the class system

Ford pushed suppliers to develop closed-loop manufacturing processes, which had the added benefit of lowering costs.

FORBES: Ford's Global Ambitions Include Turning The World's Plastic Bottles Into Car Parts

Treasury bonds, which had fallen on Wednesday as stocks rose, revered course on Thursday.

FORBES: Magazine Article