How __________ London which used to suffer from smoke and fog became so clean?did about come led to 选哪个,

分类: 作业答案 • 2022-07-19 00:05:19

问题描述：

How __________ London which used to suffer from smoke and fog became so clean?
did
about
come
led to 选哪个,

答

come
how come = why
伦敦过去都是烟雾,为什么现在变得这么干净?