单项选择题：某轮在狭水道航行，计划航向060°，选择航线正后方某单一物标进行导标方位导航，如航行

题型：问答题

阅读下面给出的两个材料，然后按要求作答

材料一：随着科学技术的发展，人们对地球形状的认识越来越正确，通过精确测量发现，地球并非正球体，不过地球极半径与赤道半径相差很少，如果把地球缩小到地球仪那样大小的时候，这个差别就看不出来了．

材料二：如图为地球半径和赤道周长示意图．

请根据以上材料一和材料二所提供的信息，提出三个地球问题（只提问题不作答）．

（1）______；

（2）______；

（3）______？

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题型：解答题

已知|m|＜1，直线l₁：y=mx+1，l₂：x=-my+1，l₁与l₂相交于点P，l₁交y轴于点A，l₂交x轴于点B
（1）证明：l₁⊥l₂；
（2）用m表示四边形OAPB的面积S，并求出S的最大值；
（3）设S=f （m），求U=S+

1

S

的单调区间．

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题型：阅读理解

阅读理解。

All too often, a choice that seems sustainable (可持续的) turns out on closer examination to be problematic.

Probably the best example is the rush to produce ethanol (乙醇) for fuel from corn. Corn is a renewable

resource-you can harvest it and grow more, almost limitlessly. So replacing gas with corn ethanol seems like

a great idea.

One might get a bit more energy out of the ethanol than that used to make it, which could still make ethanol

more sustainable than gas generally, but that's not the end of the problem. Using corn to make ethanol means

less corn is left to feed animals and people, which drives up the cost of food. That result leads to turning the

fallow land -including, in some cases, rain forest in places such as Brazil-into farmland, which in turn gives

off lots of carbon dioxide (CO) into the air. Finally, over many years, the energy benefit from burning ethanol

would make up for the forest loss. But by then, climate change would have progressed so far that it might not

help.

You cannot really declare any practice "sustainable" until you have done a complete life-cycle analysis of its

environmental (环境的) costs. Even then, technology and public keep developing, and that development can

lead to unforeseen and undesired results. The admirable goal of living sustainably requires plenty of thought on

an ongoing basis.

1. What might directly cause the loss of the forest according to the text?

A. The growing demand for energy to make ethanol

B. The increasing carbon dioxide in the air

C. The greater need for farmland

D. The big change in weather.

2. The underlined word "it" in the second paragraph refers to "_____."

A. the energy benefit

B. the forest loss

C. climate change

D. burning ethanol

3. The author thinks that replacing gas with corn ethanol is _____.

A. impractical

B. acceptable

C. admirable

D. useless

4. What does the author mainly discuss in the text?

A. Technology

B. Sustainability

C. Ethanol energy

D. Environmental protection

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题型：单项选择题

请选出Windows 2000中的磁盘配额能实现的功能（）

A.限制用户对某一FAT分区的某一文件夹的占用空间

B.限制用户对某一NTFS分区的某一文件夹的占用空间

C.根据目录名限制用户对某一NTFS分区的占用空间

D.根据文件所有者限制用户对某一NTFS分区的占用空间

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题型：多项选择题

服务的公共区域内垃圾箱、垃圾桶配置要（）。

A.配置齐全，使用方便

B.垃圾箱、垃圾桶设置标示完善，提倡环保

C.部门建立《环卫设备设施台账，垃圾箱、垃圾桶统一编号管理

D.高档，不能低调

E.全部统一种款式、颜色

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某轮在狭水道航行，计划航向060°，选择航线正后方某单一物标进行导标方位导航，如航行

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