问题 单项选择题

正常足月妊娠脐带的平均长度是()

A.30cm

B.40cm

C.55cm

D.60cm

E.70cm

答案

参考答案:C

解析:妊娠足月脐带长30~100cm,平均55cm,脐带是母儿血液气体交换、胎儿营养物质供应和代谢产物排出的重要通道,假如脐带太长或太短都会对胎儿有影响。

辨析题

多种所有制经济共同发展是我国社会主义初级阶段的一项基本经济制度。

                                                                                                                                                             

                                                                                                                                                              

                                                                                                                                                              

                                                                                                                                                              

                                                                                                                                                             

单项选择题