-Have you been here before?-This is the second time I to the Great Wall.A. comesB.

问题补充：

---- Have you been here before?

---- This is the second time I to the Great Wall.

A. comes

B. have been

C. came

D. had come

答案：

A. comes

(答案→)B. have been

C. came

D. had come

解析：考查时态：This is the 序数词或最高级+ time+从句，从句的谓语用现在完成时，句意：--以前你到过这儿吗？--这是我第二次到长城来。选B。