—Why not come and join us in the game?

—__________, but I must meet Mr Smith at his office now.

A．I’d like to.

B．Let’s go

C．Yes, please

D．It’s a pleasure

2000年是庚辰年，中华人民共和国成立50周年是干支纪年的()年;我国现正申办的奥林匹克运动会是干支纪年的()年。