离心式压缩机的主电机安装的操作步骤有（）、（）、（）、（）等。

直流电位差计扳键扳向“未知”，调节Ⅰ、Ⅱ、Ⅲ测量盘，使检流计指零，被测电压（势）为（）。

（）是表明企业经营哪几个行业的业务和生产。

A.事业领域

B.业务范围

C.利润目标

D.消费者群体的划分

剧烈胃痛首选下列哪组腧穴（）

A.中脘、足三里、建里、内关

B.脾俞、胃俞、梁丘、足三里

C.内关、公孙、中脘、足三里

D.梁丘、中脘、梁门、足三里

E.上脘、神阙、足三里、梁丘

(注：相关资料表文件存在于考生文件夹下)

Forty percent of the rats included in an experiment were male rats. If some of the rats died during the experiment and 30 percent of the rats that died were male rats, what was the ratio of the death rate among the male rats to the death rate among the female rats ？（）

A.A

B.B

C.C

D.D

E.E