正常脐带内含有
A．一条脐动脉，一条脐静脉
B．两条脐动脉，一条脐静脉
C．两条脐动脉，两条脐静脉
D．一条脐动脉，两条脐静脉
E．两条脐动脉
参考答案：B
—Can you Play cards?
—_____. [ ]
A. yes, I do
B. yes, I can't
C. No, I can't
D. No, I don't
社会主义宪法
