受血者为A型，与供血者作交叉配血试验，主侧不发生凝集，次侧发生凝集，供血者的ABO血

An assisted birth using forceps or a vacuum extractor may be performed for ineffective pushing, for large neonates, to shorten the second stage of labor, or for a malpresentation. When caring for the mother following an assisted birth, the nurse should keep which of the following in mind

A. A vacuum extractor is safer than forceps because it causes less trauma to the neonate and the mother’s perineum.
B. The neonate will develop a cephalohematoma as a result of the instrumentation.
C. The use of instruments during the birth process is a fairly rare occurrence.
D. Additional nursing interventions are needed to ensure an uncomplicated postpartum.

试述影响混凝土用水量的主要因素？

我国现行的社会保险制度中，按照规定覆盖范围最大的保险项目是哪一个（）

A.养老保险

B.医疗保险

C.失业保险

D.工伤保险

家庭代际关系主要指的是老年人与（）的关系。

液压泵按其流量分为定量泵和变量泵；液压泵经过组合后又有（）和（）等形式。