离心泵的转动部分包括()。 A.叶轮、泵轴、平衡盘、盘根 B.叶轮、泵轴、轴套、泵壳

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问题:

离心泵的转动部分包括()。

A.叶轮、泵轴、平衡盘、盘根

B.叶轮、泵轴、轴套、泵壳

C.叶轮、泵轴、轴套、平衡盘

D.叶轮、密封、轴套、泵壳

考点:液化天然气操作工LNG加气操作LNG加气操作题库
题型:单项选择题

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。

选项中有两项为多余选项。

Most people know that chocolate is made from cocoa and that the origins of chocolate can be traced back to Central and South America.  小题1: But how did chocolate go from being the food of the gods to being the food of love?

  小题2:  They established the first cocoa plantation and used the cocoa beans as the main ingredient in a dark, bitter drink that we would call “chocolate”. The Mayas believed that chocolate had mystical properties.   小题3: In fact, cocoa beans were used as a form of currency that was worth its weight in gold.

Spanish conquistador Hernando Cortez was the first European explorer to realize cocoa’s commercial possibilities.  小题4:  In 1529, Cortez returned Spain and introduced chocolate——as a drink mixed with sugar, vanilla, and cinnamon——to European society.

It caught on, especially with the nobility. As its popularity spread, people found new ways to make and use chocolate.  小题5:  Whether it is in delectable desserts or crunchy candy, people all over the world are still in love with chocolate.

A. But cocoa also had commercial value.

B. But not all the people all over the world love cocoa.

C. For centuries, the native there regarded cocoa as a gift from the gods.

D. When he arrived in the New World in 1519, he soon established his own cocoa plantation.

E. Around A. D. 600, the Mayas were the main aboriginal group in Central America.

F. These days, chocolate is enjoyed as both a tasty treat and a romantic indulgence.

G. Doctors said cocoa plays an active part in medicine.

题型:单项选择题

在做“描绘小灯泡的伏安特性曲线”的实验中,实验室提供了小灯泡(3.8 V,0.3 A)、电流表(0~0.5A,内阻约0.4)电压表(0~5V,内阻约10k)以及滑动变阻器等实验器材。

(1)如果用多用电表欧姆挡粗略测量该小灯泡的电阻,应选用的挡位是[ ]

A.×l 000

B.×100

C.×10

D.×1

(2)如果既要满足小灯泡两端电压从零开始连续变化,又要测量误差较小,应从如图所示的电路中选择哪个电路做实验电路[ ]

A.

B.

C.

D.

(3)利用实验数据画出了如图所示的小灯泡的伏安特性曲线.根据此图给出的信息可知,随着小灯泡 两端电压的升高,小灯泡的电阻____。(填“变 大”“变小”或“不变”)

题型:单项选择题

与外阴恶性肿瘤有关的病因有()

A. * * 瘤

B.尖锐湿疣

C.人 * * 状瘤病毒感染

D.外阴上皮内非瘤变

E.巨细胞病毒感染

题型:单项选择题

参加竞聘上岗人员本着自愿的原则,根据()情况,选择申报竞聘岗位。

A.岗位的好坏和本人的实际

B.岗位要求的条件和本人的实际

C.岗位要求的条件和本人的爱好

D.岗位要求的能力和本人的实际

题型:单项选择题

汇票、本票和支票都是需要承兑后方为有效的票据。

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