Do you know the Water Cube（水立方）at all?- No this is the first time I here.A. wasB.

问题补充：

--- Do you know the Water Cube（水立方）at all?

--- No, this is the first time I here.

A. was

B. have been

C. came

D. am coming

答案：

A. was

(答案→)B. have been

C. came

D. am coming

解析：考查句型结构It/This/that is/was +the first/second/...+that-clause,从句需使用完成时。这个句型结构中，如果前面是is的话，从句用现在完成时，若前面是was的话，则用过去完成时。故本题应选B。句意：——你究竟知不知道水立方？——不知道，这是我第一次来这里。