长臂卡环一般用于

A．孤立的前磨牙

B．最后孤立倾斜的磨牙

C．健康正常的基牙

D．远基牙正常、近基牙松动，但又不宜拔除仍可保留的前磨牙

E．游离缺失的基牙

—It’s years ____you broke up then.

—Yes. I have regretted the decision. It was long ____I realized I had mistaken him.

A．until; after

B．when; before

C．since; before

D．when; until