如图所示,在水平面内的直角坐标系xOy中有一光滑固定金属导轨AOC,其中曲线导

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问题:

如图所示,在水平面内的直角坐标系xOy中有一光滑固定金属导轨AOC,其中曲线导 轨OA满足方程y="isinkx" ,0C导轨与x轴重合,整个导轨处于竖直向上的勻强磁场中。现有一单位长度的电阻为R0,长为L的直金属棒从图示位置开始沿x轴正方向匀速运动距离。不计金属导轨A0C电阻和所有接触电阻,则在该直金属棒运动过程中,它与导轨组成的闭合回路

A.感应电流沿逆时针方向

B.感应电动势与进入轨道距离-成正比

C.感应电流大小和方向均不变

D.电功率不变

考点:法拉第电磁感应定律
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某矿发生45年来最大的煤矿瓦斯爆炸事故,其中,采用剃头下山开采的方式是造成事故扩大的重要原因。剃头开采存在的重大隐患有()。

A.人员过度集中,发生灾害损失扩大

B.通风系统不健全

C.易发生火灾

D.多工种交叉作业,相互干扰

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一个圆柱的侧面展开是一个正方形,这个圆柱的底面半径和高的比是(    )。

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第II卷(共45分)

第四部分:写作(共两节,满分45分)

第一节:阅读表达(共5小题;每小3分,满分15分)

阅读下面的短文,请根据短文后的要求将答案答题(请注意问题后的要求)。

She is a cute,quiet girl.As a daughter,she has no secrets from her mother, who is very pleased with her.But recently she has become somewhat mysterious(神秘的).What if she falls in 1ove,which is too early for a girl of her age?After all,she is reaching the “dangerous Stage”.These thoughts have caused trouble in the mother’s mind.

One weekend the girl came to tell her mother that she was going to the cinema with her schoolmates and would return late、This was the first time her mother had agreed,and she couldn’t help worrying because her daughter had never been away at night before.The mother waited till nine and her uneasiness(不安)got the upper hand over her. She decided to go out to meet her daughter.Just al that moment the noise of a car pul1ing up drew her to the window and there was her daughter,waving goodbye to a boy. Her heart missed a beat. When   ,the mother was watching TV,pretending that nothing had happened.“Mum,I’m back.”. “Yeah.”. “Sorry to be late. Still sitting up?” Yes,Oh,that….Who’s that boy?” The daughter was stunned(发愣)for a moment.“Ah.It’s my monitor.He gave me a lift on his way home.Mum, I’m going to bed.” “All right, Go to sleep early.”

Next morning,when the mother went to the daughter’s room to do some tidying,she found her diary left at her pillow. After a few minutes’ hesitation(犹豫),she finally opened it to the entry of the night before. it said: Mum, it was my love that made you ask, but it would show your understanding of me if you hadn't. Holding the diary,the mother felt in thought.

76.Please fill in the blank with proper words.(P1ease answer within 10 words.)

77.Which sentence in the second paragraph can be replaced by the following one? …she became nervous and worried.

78.Why was the daughter stunned for a moment after hearing her mother’s question,(P1ease answer within 15 words)

79.How might the mother feel after reading her daughter’s diary?(P1ease answer within 15 words)

80.P1ease translate the underlined sentence into Chinese.

题型:选择题

在代码编辑器中,续行符是用来换行书写同一个语句的符号,用以表示续行符的是( )。

A.123

B._name

C.class

D.1first

题型:选择题

布袋除尘器灰斗内积存大量的粉尘而可能引发的故障()。

A、过滤设备阻力增加,处理风量减少

B、清落的粉尘又被二次飞扬,使过滤器始终处于高阻运行

C、过滤设备灰斗进风口堵塞

D、使内滤式过滤器的滤袋中进入粉尘形成“香肠”状,则促使滤袋的破损、伸长等;使脉冲式过滤器的滤袋底部处于结灰,则造成底部的磨损等

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