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

未分类题阅读材料．根据要求完成教学设计任务。材料一《普通高中物理课程标准（实验）》关于“电磁感应定律”的内容要求为：“收集资料，了解电磁感应现象的发现过程，体会人类探索自然规律的科学态度和科学精神。举例说明电磁感应在生活和生产中的应用。理解法拉第电磁感应定律。”材料二某版本高中物理教科书关于“法拉第电磁感应定律”的部分教学内容如下：穿过闭合导体回路的磁通量发生变化，其中就有感应电流。既然有感应电流．电路中就一定有电动势。如果电路没有闭合，这时虽然没有感应电流，电动势依然存在。在电磁感应现象中产生的电动势叫做感应电动势。产生感应电动势的那部分导体就相当于电源。感应电动势的大小跟哪些因素有关呢?在用导线切割磁感线产生的感应电流的实验中，导线运动的速度越快、磁体的磁场越强，产生的感应电流就越大：在向线圈中插入条形磁铁的实验中，磁铁的磁场越强、插入的速度越快．产生的感应电流就越大。这些经验向我们提示，感应电动势可能与磁通量变化的快慢有关，而磁通量变化的快慢可以用磁通量的变化率表示。材料三教学对象为高中二年级学生，学生已经学习了磁场、楞次定律等知识。（1）简述法拉第电磁感应定律的内容。（2）结合所给材料，完成“法拉第电磁感应定律”的教学设计，内容包括教学目标、教学过程。

未分类题某教师为了了解学生对力的概念的掌握与运用情况，设计了若干检测题，其中一题如下。甲、乙两人手拉手玩拔河游戏，结果甲胜乙败，那么甲乙两人谁受拉力大?【错解】因为甲胜乙，所以甲对乙的拉力比乙对甲的拉力大。就像拔河一样，甲方胜一定是甲方对乙方的拉力大。针对上述材料．回答下列问题：（1）分析学生答题错误可能是由哪些原因造成的。（2）针对其中由物理知识方面导致的错误，给出正确的引导，用于帮助学生学习。

未分类题关于振动和波动，下列说法错误的是（ ）。