Question

Only when _______ home_____ that he had left his bag in the taxi he had taken.

A．he returned; did he realize	B．did he return; did he realize
C．he returned; he realized	D．did he return; he realized

Answer 1

A

考查倒装。Only + 状语从句，从句不倒装，主句的主谓要倒装，，故选A。