搜题请搜索小程序“爱下问搜题”
问题 单项选择题

对3个直径为30mm、长为50mm，有周向缺陷的圆柱体试件进行磁粉探伤时，正确的操作工艺是（）。

A.将3个试件沿轴向连接在一起，平行于线圈轴置入线圈中。用连续法施加磁粉，先取中间的试件进行观察，然后再将端部的一个换入中间，重复进行探伤

B.将单个试件放入线圈中央，用连续法施加磁粉进行观察

C.把3个试件沿轴向连接在一起，用轴向通电法磁化，用连续法进行探伤

D.单个用轴向通电法磁化，连续法进行探伤

答案

参考答案：A

多项选择题

在消防设施档案的保存期限中，存档时间不少于5年的消防设施档案包括（）

A.《消防控制室值班记录表》

B.《建筑消防设施巡查记录表》

C.《建筑消防设施检测记录表》

D.《建筑消防设施维护保养计划表》

E.《建筑消防设施维护保养记录表》
查看答案
单项选择题

The history of African—Americans during the past 400 years is traditionally narrated (1) an ongoing struggle against (2) and indifference on the part of the American mainstream, and a struggle (3) as an upward movement is (4) toward ever more justice and opportunity.

Technology in and of (5) is not at fault; it’s much too simple to say that gunpowder or agricultural machinery or fiber optics (6) been the enemy of an (7) group of people. A certain machine is put (8) work in a certain way—the purpose (9) which it was designed. The people who design the machines are not intent on unleashing chaos; they are usually trying to (10) a task more quickly, cleanly, or cheaply, (11) the imperative of innovation and efficiency that has ruled Western civilization (12) the Renaissance.

Mastery of technology is second only (13) money as the true measure of accomplishment in this country, and it is very likely that by (14) this under-representation in the technological realm, and by not questioning and examining the folkways that have (15) it, blacks are allowing. (16) to be kept out of the mainstream once again. This time, however, they will be (17) from the greatest cash engine of the twenty-first century. Inner-city blacks in particular are in danger, and the beautiful suburbs (18) ring the decay of Hartford, shed the past and learn to exist without contemplating or encountering the tragedy of the inner city.

And blacks must change as well. The ways that (19) their ancestors through captivity and coming to freedom have begun to loose their utility. If blacks (20) to survive as full participants in this society, they have to understand what works now.

8（）

A.for

B.off

C.on

D.at
查看答案