如图:OP、O'P'是两条来源于同一物点S(图中没画出)的反射光线,请找出平面镜

题型:操作题

问题:

如图:OP、O'P'是两条来源于同一物点S(图中没画出)的反射光线,请找出平面镜上方的物点S和下方的像点S',并画出完整的光路图.

考点:平面镜成像的相关作图光的反射的光路图
题型:操作题

瞬时停电,贫溶剂泵自启,但贫溶剂进料量不上来,是什么原因?

题型:操作题

我国发射的宇宙飞船在完成任务后,返回地面指定地点,宇宙飞船在下落到地面附近时,由于空气阻力作用做匀速直线运动,则宇宙飞船在匀速下降的过程中,它的[ ]

A.动能不变,势能减小,内能增大  

B.动能不变,势能增大,内能减小

C.动能减小,势能不变,内能增大  

D.动能增大,势能减小,内能不变

题型:操作题
电气化铁路的输电线常用图所示的方式悬挂在钢缆上.钢缆的A端固定在电杆上,B端连接在滑轮组上.滑轮组由a、b、c三个滑轮构成,配重P由多个混凝土圆盘悬挂在一起组成,配重的总重为G,若不计摩擦和滑轮的重量,则以下说法中正确的是(  )

A.a为动滑轮,B端钢缆受到滑轮组的拉力大小约为3G

B.a为动滑轮,B端钢缆受到滑轮组的拉力大小约为G

C.a、c为动滑轮,B端钢缆受到滑轮组的拉力大小约为3G

D.a、c为动滑轮,B端钢缆受到滑轮组的拉力大小约为G

题型:操作题

在软件体系结构中,基于______的系统具有某种意义上的递归性,形成了“部分—整体”的层次结构,用户可以组合多个简单的子系统以形成一些较大的子系统,这些较大的子系统又可以组合成更大的子系统。

A.解释器模式
B.分层模式
C.知识库模式
D.事件驱动模式

题型:操作题

When I was looking for a Christmas present for my daughter in a toy store, a nicely dressed little girl, with some money in her little hand, was looking at some beautiful dolls. When she saw a doll she liked, she would ask her father if she had enough money. He usually said yes.
At the same time, a boy, with old and small clothes, was looking at some video games. He, too, had money in his hand, but it looked no more than five dollars. Each time he picked up one of the video games and looked at his father, he shook his head.
The little girl had chosen her doll, a very beautiful one. However, she noticed the boy and his father. She saw the boy give up a video game with disappointment and walk to another corner of the store.
The little girl put her doll back to the shelf and ran over to the video game. After she talked to her father, she paid for the video game and whispered(耳语) to the shop assistant.
So the boy got the video game that he wanted for free—he was told it was a prize from the store. He smiled happily, although he felt it was so incredible. The girl saw all this happen. She smiled, too.
When I walked out of the store to my car, I heard the father ask his daughter why she had done that. I would never forget their short talk. " Daddy, didn’t Grandma want me to buy something that would make me happy"
He said, "Of course, she did. "
"Well, I just did!" With that, the little girl started skipping towards their car happily.

The story happened in a ______.

A.school


B.toy store
C.cinema



D.computer room

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