问题补充：
He arrived Shanghai 6:00 the morning of June 2nd.
A. at, at, in
B. in, at, on
C. in, at, in
D. at, in, on
答案：
A. at, at, in
(答案→)B. in, at, on
C. in, at, in
D. at, in, on
解析：重点考察介词 at on/in 的用法，arrive at 是固定短语。表示具体时刻是要用at 确指某一天早上，下午或晚上时要用on，故选B
