材料一：及安、史既平，武夫战将以功起行阵，为侯王者，皆除节度使，大者连州十数，小者尤兼三四，所属文武官，奚自置属，未尝请命于朝，力达势盛，遂成尾大不掉之势……自宋以臣知州事，历代因之，遂无复弱干强枝之患。宋太祖及赵普之计虑（稍夺其权、制其钱谷、收其精兵）深矣，而议者徒谓宋之弱由此，是但知御侮力薄，不足以自强，而不知消患于未萌。

——赵翼《廿二史札记》

材料二：在政府权力的制约方面，（美国）联邦宪法采用了在同一体制内对于政府权力进行两向分割，即对联邦和州政府的权力进行纵向分割，在联邦政府的层次上依三权分立的原则对中央政府的权力进行横向分割。通过联邦制和三权分立体制形成了对权力的制约与平衡，克服邦联体制下美国面临的社会危机，同时形成了新的国家体制。

——王希《原则与妥协》

材料三：第一章：总纲

第一条：中华人民共和国为新民主主义即人民民主主义的国家，实行工人阶级领导的、以工农联盟为基础的、团结各民主阶级和国内各民族的人民民主专政，反对帝国主义、封建主义和官僚资本主义，为中国的独立、民主、和平、统一和富强而奋斗。

第四条：中华人民共和国人民依法有选举权和被选举权。

第五条：中华人民共和国人民有思想、言论、出版、集会、结社、通讯、人身、居住、迁徙、宗教信仰及示威游行的自由权。

第六条：中华人民共和国废除束缚妇女的封建制度。妇女在政治的、经济的、文化教育的、社会的生活各方面，均有与男子平等的权利。实行男女婚姻自由。

①社会生产力大幅度提高     ②社会结构和世界形势因此改变

③人类的生活更加丰富多彩   ④环境污染

    A survey has shown that what you do on a plane can be determined by which nationality is listed on your passport.

    According to the results of an international passenger survey, Australians are the biggest drinkers on board with 36 percent choosing to down the hatch, compared to 35 percent of Americans and 33 percent of Brits.

    The Airline Passenger Experience Association(APEX) spoke to around 1,500 people, aged 18 and older, who have travelled by plane at least once during the last three months and were living in the United States, United Kingdom, Germany, Japan, China, Singapore, Australia and Brazil.

    The results found Chinese travelers are most likely to nod off once the seat-belt sign switches off. They are also the first to take out their credit card for some in-flight shopping and the biggest fans of gaming. Americans on the other hand like to use their time in the air more productively—when not drinking—choosing to work while flying at 35,000 feet.

    Meanwhile, Brits and Germans are the best at making chat with random strangers—spending 50 percent more time than any other nationality. Comparatively, Brazilians conduct their conversations online via email, messaging apps or social media.

    Despite plane food having a bad reputation, seven out of ten interviewees said they were happy to eat up on the selection of in-flight snacks and meals. In-flight magazines were also popular with four out of five passengers.

    The international flyers did however express their desire for better in-flight entertainment. “The industry has greatly improved the comfort, entertainment and on board service, and passengers are accepting those improvements” said Russell Lemieux, APEX executive director. “At the same time, passengers are demanding more from their air travel experiences which will drive more improvements touching all aspects of the journey. ” he added.

已知，一艘船以5km/h的速度向垂直于对岸方向行驶，航船实际航行方向与水流方向成30°角，求水流速度和船实际速度．