设函数f(x)=xlnx(x>0).(1)求函数f(x)的最小值;(2)设F(x

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问题:

设函数f(x)=xlnx(x>0).
(1)求函数f(x)的最小值;
(2)设F(x)=ax2+f′(x)(a∈R),讨论函数F(x)的单调性;
(3)斜率为k的直线与曲线y=f′(x)交于A(x1,y1)、B(x2,y2)(x1<x2)两点,求证:x1
1
k
x2
考点:函数的单调性与导数的关系函数的最值与导数的关系
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下面关于我国植被问题的叙述中,错误的是(  )

A.我国森林覆盖率大大低于全世界的平均水平

B.我国人均森林面积为世界人均水平的一半

C.目前,我国生态系统呈衰退的趋势

D.我国是土地沙漠化比较严重的国家之一

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阅读下列材料:

1901年,法国考古队在伊朗古城苏萨遗址发现一根黑色的玄武岩石柱。石柱上端是浮雕,下端刻满法典条文。法典分序言、正文、结语三大部分,正文部分共282条,其中有35条已经磨损,但根据在苏萨及其他地方发现的泥板文书上的法典抄本片段,大部分得以补上。石柱现存巴黎卢浮宫博物馆。下图为石柱上部的浮雕。

请回答:

(1)浮雕中站立的人物是法典的颁布者,法典因此得名。根据已有知识判断,这个人物是谁?他的身份是什么?

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(2)浮雕中的画面对法典的来源做了什么样的诠释?

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(3)石柱和其他泥板文书上使用的应为何种文字?

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(4)这部法典在历史上的地位(影响)如何?

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Most people would be (1) by the high quality of medicine (2) to most Americans. There is a lot of specialization, a great deal of (3) to the individual, a (4) amount of advanced technical equipment, and (5) effort not to make mistakes because of the financial risk which doctors and hospitals must (6) in the courts if they (7) things badly.

But the Americans are in a mess. The problem is the way in (8) health care is organized and (9) . (10) to pubic belief it is not just a free competition system. The private system has been joined a large public system, because private care was simply not (11) the less fortunate and the elderly.

But even with this huge public part of the system, (12) this year will eat up 84.5 billion dollars—more than 10 percent of the U. S. Budget—large number of Americans are left (13) . These include about half the 11 million unemployed and those who fail to meet the strict limits (14) income fixed by a government trying to make savings where it can.

The basic problem, however, is that there is no central control (15) the health system. There is no (16) to what doctors and hospitals charge for their services, other than what the public is able to pay. The number of doctors has shot up and prices have climbed. When faced with toothache, a sick child, or a heart attack, all the unfortunate persons concerned can do is (17) up. Two thirds of the population (18) covered by medical insurance. Doctors charge as much as they want (19) that the insurance company will pay the bill.

The rising cost of medicine in the U. S. A. is among the most worrying problems facing the country. In 1981 the country’s health bill climbed 15.9 percent--about twice as fast as prices (20) general.

4()

A.countless

B.titanic

C.broad

D.vast

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皮肤过敏试验阳性可用脱敏注射的是

A.青霉素
B.链霉素
C.碘造影剂
D.头孢唑林钠
E.破伤风抗毒素

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用于人力操作作业的小型机具有()。

A.手动叉车

B.手车

C.手推车

D.手扶拖拉机

E.手动升降平台

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