直流接触器常用电压等级为()V。 A.380 B.220 C.500 D.127

题型:单项选择题

问题:

直流接触器常用电压等级为()V。

A.380

B.220

C.500

D.127

考点:数控车工考试中级数控车工中级数控车工题库
题型:单项选择题

短文改错(共10小题,每题1.5分,满分15分)

The village was always very quietly .The people living     小题1:______

there were busy about working in their fields during the    小题2:______

day and went to bed early at night, tiring after a                    小题3:______

long day ’s hard work. All of them had lived in a                   小题4:__ 

village for all their life and had never left for less than       小题5:______

one day at a time. On these days how they left, they got    小题6:___

up early in the morning .They filled with their cart of               小题7:_____

fruit ,vegetables and sheeps, and went to the                    小题8:_______

market in the town beyond their valley .They come            小题9:_______

back in the evening with some money and perhaps a           小题10:____

present for their children. That was their life-hard and

simple, but not unhappy 

题型:单项选择题

三个共点力的大小分别为8N、7N、6N则它们的合力的最大值和最小值分别为(  )

A.21N、5N

B.21N、4N

C.21N、11N

D.21N、0N

题型:单项选择题

排卵后在体内卵子的寿命是()。

A.24小时

B.8小时

C.2天

D.3天

E.8小时

题型:单项选择题

当锻件设备吨位一定时,接触面积越大,单位面积上的压力就越小,因此变形深度就()。

A、不变

B、越大

C、越小

题型:单项选择题

密度为10kg/m3的正确读法是()。

A.10千克每立方米

B.10千克每三次方米

C.10千克每米三次方

D.每三次方米10千克

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