阅读下列材料，完成教学设计。
材料一动能与势能的相互转化物体自由下落或沿光滑斜面滑下时．重力对物体做正功，物体的重力势能减少。减少的重力势能到哪里去了?我们发现，在这些过程中，物体的速度增加了，表示物体的动能增加了。这说明，物体原来的重力势能转化成了动能。
原来具有一定速度的物体，由于惯性在空中竖直上升或沿光滑斜面上升，这时重力做负功，物体的速度减小，表示物体的动能减少了。但由于物体的高度增加，它的重力势能增加了。这说明，物体原来具有的动能转化成了重力势能。
材料二在只有重力或弹力做功的物体系统内，动能与势能可以互相转化，而总的机械能保持不变。这叫做机械能守恒定律。它是力学中的一条重要定律，是普遍的能量守恒定律的一种特殊情况。
根据上述材料，回答：
（1）设计一个关于机械能守恒定律内容和条件的教学导入。
（2）完成材料一部分的教学设计，内容包括学情分析和教学目标。

未分类题请阅读Passage2，完成第小题。Passage 2Results showed that at least a tenth of the Harvard first-year undergraduates polled admitted to having cheated on an exam prior to starting at the university， while almost half admitted to cheating on their homework. An anonymous survey by Harvard's newspaper has revealed a surprising pattern of academic dishonesty among students entering the US universities.The survey by The Harvard Crimson was emailed to the incoming first year undergraduates;1，600 students responded. Results showed that at least a tenth of the students polled admitted to having cheated on an exam prior to starting at the university， while almost half admitted to cheating on their homework.

未分类题He had an__________habit of emptying ash trays out of his upstairs window.

未分类题How many liaisons of sound are there in the sentence 'I called you half an hour ago'?

未分类题When you talk to your boss or to your friends， you use different words. We could analyze this phenomenon with__________.

未分类题请阅读Passage l。完成第21—25小题。Passage 1It's one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before， it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse s brain.But now Wendy Ingram， a graduate student at the University of California， Berkeley， has challenged this common sense. She has found a way to'cure' mice of their inborn fear of cats by infecting them with a parasite， reported the science journal Nature.The parasite， called Toxoplasma gondii， might sound unfamiliar to you， but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans， especially pregnant women——it is linked to blindness and the death of unborn babies.However， the parasite's effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine（尿） before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell，which could indicate that the infection has caused a permanent change in mice's brains.Why does a parasite change a mouse's brain instead of making it sick like it does to humans?The answer lies in evolution.'It's exciting scary to know how a parasite can manipulate a mouse's brain this way，' Ingram said. But she also finds it inspiring.'Typically if you have a bacterial infection， you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away.'She said， but this study has proven that wrong.'This may have huge implications for infectious disease medicine.'The passage is mainly about__________. 查看材料