一本书封面的周长为68cm，长与宽的比是15：19，这本书封面长和宽分别为多少？

已知集合A={0，2，a²}，B={1，a}，若A∪B={0，1，2，4}，则实数a的值为______．

过去一年，政府自身改革和建设取得了新的成绩，但与人民的期待仍有不小差距。
政府职能转变还不到位，行政效率有待提高，形式主义、官僚主义比较突出，腐败现象在一些地方、部门和领域比较严重。这些问题必须下大气力解决。要紧紧围绕保增长、保民生、保稳定这个大局，加强政府自身建设。
坚持依法行政。规范行政行为，做到合法行政、合理行政、程序正当、高效便民、诚实守信、权责统一。深入贯彻《行政许可法》，继续推进行政审批制度改革，减少行政许可和审批事项，特别要减少投资审批、项目核准，落实企业的投资主体地位。里，组织调动各种社会资源，促进经济增长。通过全面正确履行政府职能，创造良好发展环境，增强企业投资的信心，增强社会消费的信心，增强人民群众对国家发展的信心。
实行科学民主决策。各项决策都要做到程序( )、过程( )、结果( )。政府重大决策的形成和执行都要加强调查研究，做到乙，尊重客观规律，提高决策的预见性、科学性和有效性，要推进政务公开，增加透明度，保障人民群众的知情权、参与权、表达权、监督权，让人民群众知道政府在想什么、做什么，赢得人民群众的充分理解、广泛支持和积极参与。今年政府投资力度大、新上项目多，要确保监管到位，决不能搞劳民伤财的“形象工程”和脱离实际的“政绩工程”，绝不允许利用扩大公共投资为单位和个人谋取私利。各级政府都要自觉接受人大监督和政协民主监督，强化监察、审计等专门监督，高度重视人民群众监督和新闻舆论监督，做到行 * * 力运行到哪里，监督就落实到哪里，财政资金运用到哪里，审计就跟进到哪里。
切实转变工作作风。各级政府要坚定地贯彻中央的决策部署，紧密结合实际，创造性地开展工作，使中央的各项政策落到实处，收到实效。领导干部要深入调查研究，及时发现问题，解决问题；丙。政府工作人员要始终保持昂扬向上、奋发有为的精神状态，和广大人民群众一道知难而进，开拓进取，艰苦奋斗，共克时艰。
加强廉政建设和 * * 败工作。以规范制度和制约权力为核心，针对腐败现象易发多发的领域和环节，从源头上防止腐败。坚决查处腐败案件，依法惩处腐败分子。我们一定要勤勉尽责，以实际行动和工作业绩，建设丁的政府，让人民放心，让人民满意。

下面的理解不符合原文的一项是( )。

A．与人民的期待相比，过去的一年，政府形式主义、官僚主义和腐败现象等问题还在一定程度上、一定范围内存在
B．政府自身建设要围绕经济又好又快增长、人民安居乐业、社会和谐稳定这个大局
C．推进行政审批制度改革，就是要减少投资审判、项目核准，落实企业的投资主体地位
D．在对待“形象工程”、“政绩工程”和公共投资的问题上，中央是持坚决反对和严厉打击的态度

The world's oceans have warmed 50 percent faster over the last 40 years than previously thought due to climate change, Australian and US climate researchers reported on Wednesday. Higher ocean temperatures expand the volume of water, contributing to a rise in sea levels that is submerging small island nations and threatening to great damage in low-lying, densely-populated delta regions around the globe.

The study, published in the British journal Nature, adds to a growing scientific chorus of warnings about the pace and consequences of rising oceans. It also serves as a corrective to a massive report issued last year by the Nobel-winning UN Intergovernmental Panel on Climate Change（IPCC）, according to the authors.

Rising sea levels are driven by two things: the thermal（热）expansion of sea water, and additional water from melting sources of ice. Both processes are caused by global warming. The ice sheet that sits at the top of Greenland, for example, contains enough water to raise world ocean levels by seven metres（23 feet）, which would bury sea-level cities from Dhaka to Shanghai.

Trying to figure out how much each of these factors contributes to rising sea levels is critically important to understanding climate change, and forecasting future temperature rises, scientists say. But up to now, there has been a confusing gap between the projections of computer-based climate models, and the observations of scientists gathering data from the oceans.

The new study, led by Catia Domingues of the Centre for Australian Weather and Climate Research, is the first to reconcile（与…一致）the models with observed data. Using new techniques to assess ocean temperatures to a depth of 700 metres（2,300 feet）from 1961 to 2003, it shows that thermal warming contributed to a 0.53 millimetre-per-year rise in sea levels rather than the 0.32 mm rise reported by the IPCC.

64. What happens when the ocean's temperature rises?

A. It causes sea levels to rise.

B. It causes sea levels to remain constant.

C. It causes sea levels to decrease.

D. It causes sea level to change.

65. Which of the followings would be buried by the rising sea?

A. Small island nations.

B. All coastal cities around the world.

C. People who enjoy holiday on the beach.

D. Low-lying regions.

66. The new study in this passage _____________.

A. shows that thermal warming contributed to a 0.32 millimeter-per-year rise in sea levels.

B. did not reveal anything that scientists hadn't already known.

C. used new techniques to assess ocean temperatures.

D. shows that models contradict the observed data.

67. What was the main finding of the study?

A. Nothing enough is being done about global warming.

B. That ocean waters have warmed faster than scientists had previously thought.

C. That the warming of the world's oceans is not a threat.

D. A massive report issued last year by IPCC was wrong.

竞争性拮抗药的特点为

A．本身不能产生生理效应

B．本身能产生生理效应

C．与受体结合是可逆的

D．能抑制激动药的最大效应

E．使激动药的量效曲线平行右移