It was the first time that I the sports meeting with so large an audienceA. had joinedB.

问题补充：

It was the first time that I the sports meeting with so large an audience

A. had joined

B. have taken part in

C. have joined

D. had taken part in

答案：

A. had joined

B. have taken part in

C. have joined

(答案→)D. had taken part in

解析： 考察固定句式和时态。本题的固定句式为：It/This is/was the序数词 time that从句，句意：是某人第几次做某事的时候了。如果前面是is，后面就使用现在完成时；如果前面是was，后面就是过去完成时。本题前面使用了过去时was，说明后面使用过去完成时。故D正确。