大全680

1.        Tenor George Shirley sang more than 20 leading roles at the Metropolitan Opera since having his debut there as Fernando in Cosifan tulle on October 24, 1961.

(A) sang more than 20 leading roles at the Metropolitan Opera since having

(B) sang more than 20 leading roles at the Metropolitan Opera since having had

(C) has sung more than 20 leading roles at the Metropolitan Opera since

(D) has sung more than 20 leading roles at the Metropolitan Opera after（C）

(E) has sung more than 20 leading roles at the Metropolitan Opera subsequently to

我的问题为什么不对,after也可以引导一个时间点,主句用完成时.