- 最近，你们班就“是否应该帮助陌生人”展开了讨论，同学们就这一话题意见不一，你的看法如何?根据所提供的信息，以“ Should we help strangers?"为题，写一篇短文。要求：①表达清楚，语法正确，上下文连贯; ②必须包括表格中所有的相关信息，并适当发挥; ③词数 100 左右(短文的开头已给出，不计入总词数) ; ④不得使用真实姓名、校名和地名等。 参考词汇：美德 virtue Should we help strangers?Recently our class had a discussion about whether we should help strangers. Different students have different opinions. _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________
- 句子翻译：让我一个人待着，以便我能想出一个好主意。
- 句子翻译：我认为这是我所看过的最有趣的电影。
- 句子翻译：这些句子必须都记在笔记本上吗?
- 句子翻译：大雨使得我们没能放成风筝。
- 句子翻译：警方正忙于查明事故的原因
- 阅读下面短文，掌握大意，然后从每题所给的A、B、C、D四个选项中选出最佳选项。Once, there was a beautiful girl who didn ’t like herself, because she was blind, she couldn ’t see anything. In fact, the girl __11__ nobody except her boyfriend, for he was always __12__ to help her. She used to tell her boyfriend, “ __13__ I could see the world, I would marry you. ” One day, someone donated* a pair of __14__ to the girl. When the bandages* came off ，she was able to see __15__ ,including her boyfriend for the __16__ time. He asked her, “Now that you can see the world, will you __17__ me?” The girl looked at her boyfriend and was greatly surprised to see that he was blind, __18__ . She had never expected that, and she would not like to be with a blind husband for the rest of her li fe, so she __19__ to marry him. Her boyfriend left in tears and a few days later wrote a __20__ to her, saying, “My dear, take good care of your eyes. Before they are yours, they were __21__ .” So, this is how the human brain* often works when our status* changes. Only a very few remember __22__ life was like before. And we often ask for more than we need. Life is a gift. Today, before you complain about the __23__ of your food ，think of those who have nothing to __24__. Before you complain about life ，think of some ones who went to heaven* too early. Before you complain about your old __25__ , think of the people who are living in the streets. And when you are ti red and complain about your job, think of those who have no jobs. In a word, enjoy the things you have and don ’t forget your past.
- (1)静电场可以用电场线和等势面形象描述。a.请根据电场强度的定义和库仑定律推导出点电荷Q的场强表达式;b.点电荷的电场线和等势面分布如图所示，等势面S?S?到点电荷的距离分别为r ?、r ?。我们知道，电场线的疏密反映了空间区域电场强度的大小。请计算S?、S?上单位面积通过的电场线条数之比N1/ N2。 (2)观测宇宙中辐射电磁波的天体，距离越远单位面积接收的电磁波功率越小，观测越困难。为了收集足够强的来自天体的电磁波，增大望远镜口径是提高天文观测能力的一条重要路径。2016年9月25日，世界上最大的单口径球面射电望远镜FAST在我国贵州落成启用，被誉为“中国天眼”。FAST直径为 500 m，有效提高了人类观测宇宙的精度和范围。a.设直径为 100 m的望远镜能够接收到的来自某天体的电磁波功率为P?，计算 FAST能够接收到的来自该天体的电磁波功率P?;b.在宇宙大尺度上， 天体的空间分布是均匀的，仅以辐射功率为 P的同类天体为观测对象，设直径为 100 m望远镜能够观测到的此类天体数目是N0，计算 FAST能够观测到的此类天体数目 N。
- 如图 1所示， 用电动势为 E、内阻为 r 的电源， 向滑动变阻器 R供电。改变变阻器 R的阻值，路端电压 U与电流 I 均随之变化. （1）以U为纵坐标，I 为横坐标，在图 2中画出变阻器阻值 R变化过程中 U- I 图像的示意图，并说明 U-I 图像与两坐标轴交点的物理意义。（2）a．请在图 2画好的 U- I 关系图线上任取一点，画出带网格的图形，以其面积表示此时电源的输出功率；b．请推导该电源对外电路能够输出的最大电功率及条件。（3）请写出电源电动势定义式，并结合能量守恒定律证明：电源电动势在数值上等于内、外电路电势降落之和。
- 2022 年将在我国举办第二十四届冬奥会，跳台滑雪是其中最具观赏性的项目之一。某滑道示意图如下，长直助滑道AB与弯曲滑道 BC平滑衔接，滑道BC高 h=10 m，C是半径 R=20 m 圆弧的最低点，质量m=60 kg 的运动员从 A处由静止开始匀加速下滑，加速度 a=4.5 m/s2，到达 B点时速度 vB=30 m/s 。取重力加速度 g=10 m/s 2。（1）求长直助滑道AB的长度 L；（2）求运动员在 AB段所受合外力的冲量的I 大小；（3）若不计 BC段的阻力，画出运动员经过C点时的受力图，并求其所受支持力FN的大小。
置顶