问题 单项选择题

检查离心泵过程中,罐液位应在泵入口管线(),保证正压头。

A.以上

B.以下

C.同一水平面

D.不一定

答案

参考答案:A

仔细观察法国大革命时期的三幅图片,回答问题:

请回答:

(1)图(1)反映了怎样一种社会状况?

                                                                                                                                                           

(2)请你用简洁的语言介绍图(2)反映的历史事件。它标志着什么?这一天对法国有什么影响?

                                                                                                                                                            

                                                                                                                                                            

(3)图(3)反映的是什么历史事件?

                                                                                                                                                            

(4)图(1)与图(2)、图(3)之间有什么关系?

                                                                                                                                                            

                                                                                                                                                            

多项选择题