We will celebrate the 90th birthday of the Chinese Communist Party June 29th in Qinz

问题补充：

We will celebrate the 90th birthday of the Chinese Communist Party June 29th, in Qinzhou.

A. on

B. at

C. in

D. during

答案：

(答案→)A. on

B. at

C. in

D. during

解析：此题考查介词的基本用法，确指某一天时要用介词on。