When Edison was very young ,he liked to find out how ___.

问题描述:

When Edison was very young ,he liked to find out how ___.
A.did things work B.do things work C.things work D.things worked

选D 这里考察宾语从句用陈述句语序的知识.即主语在前,谓语在后.C中时态不对,A和B中不能要助动词