【题目】My skating teacher was really great and ______ I knew it, I was able to skate!
A.beforeB.since
C.untilD.after
在线课程【答案】A
【解析】
考查连词辨析。句意：我的滑冰老师真的很棒，在我知道这一点之前，我已经会滑冰了。A. before在……之前；B. since自从；C. until直到；D. after在……之后。根据“I knew it, I was able to skate!”可知此处表示“在……之前”，故A项正确。