I thought horseback riding would be the sport for me until I fell down from the horse back

问题补充：

I thought horseback riding would be the sport for me until I fell down from the horse back .As you can imagine ,I haven’t been invited back .

A. later

B. since

C. after

D. ever

答案：

A. later

(答案→)B. since

C. after

D. ever

解析：自从我从马背上摔下来后，再也未参加骑马运动。since :adv 从…以后。故选B。