先看下面两道高考题:1. (MET 1993)-What was the party like?-Wonderful. It's years__I enjoyed myself so much.A. after B. before C. when D. since2. (NMET 1998) It was only when I reread his poems recently_I beganto appreciate their beauty.A. until B.that C.then D.so 这两道高考题主要考查由it引导的复合句中的连接词或动词时态的用法。