在进行汽包炉化学清洗时,如汽包的水位偏低,将() A.对清洗结果有影响,但不大 B.

题型:单项选择题

问题:

在进行汽包炉化学清洗时,如汽包的水位偏低,将()

A.对清洗结果有影响,但不大

B.造成清洗循环回路短路,使锅炉的受热面得不到彻底清洗

C.会使清洗的腐蚀速率增大

D.容易产生二次锈

考点:气体分馏装置操作工初级气体分馏装置操作工初级气体分馏装置操作工题库
题型:单项选择题

(1)在研究平抛物体运动的实验中,用一张印有小方格的纸记录轨迹,小方格的边长L=1.25 cm,若小球在平抛运动途中的几个位置如图中的a、b、c、d所示,则小球平抛的初速度的计算式v0=________(用L、g表示),其值是________。(g=9.8 m/s2

(2)在“研究平抛运动”实验中,应采取下列哪些措施减小实验误差? [ ]

A.斜槽轨道末端切线必须水平

B.斜槽轨道必须光滑

C.每次要平衡摩擦力

D.小球每次应从斜槽同一高度释放

题型:单项选择题

普罗帕酮为广谱高效抗心律失常药。下列说法正确的是:

A.可用溴水或FeCl3溶液鉴别X和Y

B.反应物X与中间体Y互为同系物

C.普罗帕酮分子中有2个手性碳原子

D.X、Y和普罗帕酮都能发生加成、水解、氧化、消去反应

题型:单项选择题

According to an old story, a farmer once found that a bag of corn had been stolen from his house. He went to the judge and told him about his loss. The judge ordered all the people of the farm to come before him. He took a number of sticks of equal length and gave one stick to each man.

 He then said, “Come before me again tomorrow. I shall then know which of you is the thief because the stick given to the thief will be one inch longer than the others.”

 The thief was afraid of being found out, and so he cut an inch off his stick. The next day the thief’s stick was found to be one inch shorter than any of the others. In this way the thief was found out, and was at once taken away to prison.

小题1:The judge gave each man a stick _______.

A.to change back the farmer’s corn

B.to beat the thief

C.as a tool to find out the thief

D.so as to play a game together小题2:Since the thief cut the stick short, ________.

A.he was found out

B.the judge couldn’t catch him

C.his stick had an equal length with the others’

D.his stick wouldn’t be any longer小题3:The wise way the judge found out the thief in the end was to make ______.

A.the thief cut the stick off

B.the thief cut an inch off the stick

C.the stick grow an inch longer

D.the other’s sticks would become one inch shorter

题型:单项选择题

测量系统差压计的误差应小于示值的()

A、1%

B、0.1%

C、0.2%

D、2%

题型:单项选择题

以下软件是图像加工工具的是()

A、Photoshop

B、Excel

C、Winrar

D、Frontpage

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