定群研究，又称A．队列研究 B．现况凋查 C．病例对照调查 D．临床随访研究 E．实

直角都比不是直角的角大。[ ]

如图所示，人站在岸上通过定滑轮用绳牵引小船，若水的阻力恒定不变，则在船匀速靠岸的过程中

[ ]

A．绳的拉力不断增大　　　

B．绳的拉力保持不变

C．绳的拉力不断减小　　　

D．绳的拉力先增大后减小

喉 * * 状瘤与________感染有关。

Tragedies have a way of making people rethink their (1) and find a new focus. They make people think about what a society needs in order to (2) . The notion of doing something to take control of society or of our fate as humans might be dated back to ancient times of the (3) . Now, in the early 21st century, " social (4) " are trying to take back some (5) over society’s direction once again. A social inventor is not necessarily a social (6) , a social (7) or someone who works in a (8) industry or invents new (9) and consumer products. A social inventor is using the power of (10) thinking, to come up with ideas for (11) in certain communities or sections of society. They have a vision of a (12) world and create new systems or practices. Their ideas may seem (13) or impossible. They are usually quite (14) people. But some of these creative thinkers have (15) and quietly changed the way we live. Social inventions do not have to be (16) . Sometimes they are new (17) for neighborhoods or communities, or even very (18) ideas. The idea of social inventions has become so popular in recent years. It shows how much people desire to make a (19) in our society and not remain (20) .

Tragedies have a way of making people rethink their (1) and find a new focus. They make people think about what a society needs in order to (2) . The notion of doing something to take control of society or of our fate as humans might be dated back to ancient times of the (3) . Now, in the early 21st century, " social (4) " are trying to take back some (5) over society’s direction once again. A social inventor is not necessarily a social (6) , a social (7) or someone who works in a (8) industry or invents new (9) and consumer products. A social inventor is using the power of (10) thinking, to come up with ideas for (11) in certain communities or sections of society. They have a vision of a (12) world and create new systems or practices. Their ideas may seem (13) or impossible. They are usually quite (14) people. But some of these creative thinkers have (15) and quietly changed the way we live. Social inventions do not have to be (16) . Sometimes they are new (17) for neighborhoods or communities, or even very (18) ideas. The idea of social inventions has become so popular in recent years. It shows how much people desire to make a (19) in our society and not remain (20) .

某公司拟在沿海地区选址建厂，主要是生产某大型客机。年产量为200架，原材料大部分进口，产品大部分出口。合作期限10年，基准收益率为12%。经过收集有关数据，确定了两个厂址选择方案，现给出了4个评价厂址方案的指标：劳动力素质、运输条件、基础设施和投资政策。权重分别为0.25、0.35、0.15和0.25。分项评价结果如表1-1所示。
　　　　　　　　　　　　　　　　　　　　　　　　　　表1-1　两个方案综合评价

指标		劳动力素质	运输条件	基础设施	投资政策
		0.25	0.35	0.15	0.25
方案	1	7	6	8	9
	2	8	6	7	9

　　问题1．若采用系统分析方法为该工厂选址，应该采取哪些步骤
2．采用综合评价的加权平均法(应用加法规则)对两个方案进行评价，哪个方案更优
3．这种综合评价法有哪些局限性