My little brother was born _______ a rainy day _______ summer, and our family name is exactly "Xia". So we

call him "Xia Yu". [ ]

A. on, at

B. on, in

C. at, in

D. in, on

标准水准点一般为（）点及以上，在使用前必须进行校核。

A、1

B、2

C、3

D、4