Question

Not until the early years of the 19th century _________．

[　　]

A．

man did know heat is what

B．

man know what is heat

C．

did man know what heat is

D．

didn’t man know heat

Answer 1

答案：C
解析：

本句考查倒装结构，否定词not置于句首强调状语时主句需要倒装，故C项正确。