The boy was born ________ the 3rd of July, 1989. [ ]
A. in
B. on
C. at
答案：B
遗传咨询分为（）。
A.婚前咨询
B.婚后咨询
C.产前咨询
D.一般遗传咨询
E.特殊遗传咨询
简述设计露天采场底宽时，其最要求。小尺寸应满足哪些要求？
