问题
选择题
Only when I made it to the train station _______ that I had left my ticket at home.
A．have I realized
B．did I realize
C．had I realized
D．would I realize
答案
答案：B
考查倒装句。Only +状语放在句首，使用部分倒装。从句不倒装，主句倒装。此题是Only+时间状语放在句首，根据时态应选B。