材料  美国独立后，各大城市的市议会开始选举市长，但市长无权否决市议会的决定，许多行政部门的首长不对市长而是对议会负责；同时，城市权力还受到州议会的掣肘，造成城市管理的极大混乱。随着城市化进程的扩大，越来越多的城市事务如教育、警察、垃圾和污水处理等，由原来私人公司承担的这些责任转移到市政府肩上，带来了城市功能和财政支出的扩张。然而，随之而来的是城市老板（城市中的职业政治家）乘机弄权，效率低下；有人指出：“即使不是所有的老板都生财有道，但到死身无分文的也没几个。”市政改革被提上议事日程。各州陆续制定城市宪章，废除了州政府对城市公共卫生、警察、公园和其他一些机构的人事任命权，实现了城市自治。在城市内部，到19世纪未，许多市议会“丧失了预算以外的所有拨款权力”，市政服务的其他权力也转到市长手中，以市长为代表的行政力量逐渐成为与老板集团所控制的（市）议会相抗衡的力量。改革派倡导了一系列的选举制度改革，如选民登记、全市大选和非竞选举，以削弱老板集团对市政的控制与渗透。改革派还改革市政机构，按照商业管理原则运行政府，任用专家治理城市。然而，城市治理毕竟不是企业管理，为了效率而不顾政策的社会效果，危害了下层民众的利益。

──据钱乘旦总主编《世界现代化历程》

如图所示，悬挂的直杆AB长L=20m，在距其下端h=5m处，有一长为L'=20m的无底圆筒CD，若将悬线剪断，则：

已知集合A={x|﹣2≤x≤3}，B={x|1＜x＜6}．

（1）求A∪B；

（2）设C={x|x∈A∩B，且x∈Z}，写出集合C的所有子集．

     A serious earthquake can be a terrible experience, and it is easy to forget safety measures(措施) in disorder(混乱). Fortunately, most earthquake safety measures are common sense, but if you forget everything else, re­member the following instructions: drop, cover, and hold on. Also, most of earthquake deaths hap­pen after the earthquake, so remember that the danger does not end when the shaking does!

     If you stay indoors during an earthquake, move away from unsupported areas and windows. Try to get under a doorway or another area of the building which is held up by strong beams(梁).  Stay under a table or desk only if it is very strong. Do not rush to lifts, because it is far safer to stay where you are. Cover your head with your arms around it and curl (蜷缩) into a ball, and wait for the shaking to stop.

     If you stay outdoors during an earthquake, move to an area which is as open as possible. Don't move to build­ings, electric poles and other objects which may fall during an earthquake and injure you. Protect your head and stay low to the ground till the shaking ends and it is safe to move.

     After an earthquake, many buildings are less strong, although they appear safe. If you stay indoors, move people from the building quickly and help disabled or injured people. Once outdoors, move well away from the building so that if it falls down, you will not be injured. Wait till public safety officials an­nounce that it is safe to stay indoors.

     By planning ahead and keeping calm during an earthquake, you can greatly increase your chances of survival(生存) without injury.

下图是鸡蛋各部分质量统计图。从图中我们可以算出：蛋白的质量占总质量的____％。如果一个鸡蛋重80克，那么这个鸡蛋中的蛋白重____克。