t为任意有理数，点（-t2-3，t2+1）总在（ ） A．第一象限 B．第二象限

常用固体润滑剂有石墨、（）、聚四氟乙烯等。

A、润滑脂

B、润滑油

C、二硫化钼

D、锂基润滑脂

阅读理解。

      On a cloudy aftemoon last September, Rubio watched Texas National Cuard soldiers help passengers

off planes at a small airport near College Station. All of them were running away from Hurricane (飓风) Ike.

They had something else in common as well. Each passenger wore a bright yellow wristband (腕标), RFID,

developed by Rubio's company. The wristband had a computer chip (芯片), which allowed the state's

emergency response center (急救中心) to follow the person who wore it.

     "The wristband really made a difference," says Rubio, adding that thousands of families who called the

state's emergency response center during the hurricane were able to find loved ones. The wristbands also

made a lot of money for Rubio's company.

     That's a goal Rubio could not have imagined even a few years ago, as a 36-year-old stay-at-home mum

with three kids under ten and a husband who traveled for work five days a week. "All I wanted was to have

my family back together," she says.

     Rubio considered doing something different after the birth of her third child and returned to work. A friend

suggested the technology of RFID. It wasn't new but was mainly used to find packages. 

    Rubio began imagining wider use of RFID, and in 2005 the wristband appeared at a business conference and

did a good job. In the wake of Hurricane Katrina, the company further used the technology, and later during

Ike about 27,000 people were successfully saved.

     "I'm a mum with three kids or a woman in a technology field. I've succeeded and got confidence (信心)."

Rubio also achieved something else. She finally has the family life she always wanted.

1. People wore wristbands during Hurricane Ike in order to ________.

A. protect them from being hurt

B. be allowed to get on the planes

C. lead their way to a safe place

D. be found easily by other people

2. Rubio decided to return to work because ________.

A. she wanted to make money

B. she liked the new technology

C. she needed a change in life

D. she was used to hard work

3. How did the wristband work according to the passage? 

A. Very well.

B. All right.

C. Not well.

D. Very badly.

4. What does Rubio think is the most important?

A. Usual business.

B. Family life.

C. Creat success.

D. Social position.

锌钡白是BaSO₄和ZnS的混合物，ZnS难溶于水。某化工厂用重晶石为原料制备锌钡白，生产过程中会产生大量废气（主要成分为CO₂、CO及少量SO₂和硫蒸气等），为防止污染空气并提高原料利用率，生产中采用下述工艺流程

请根据上述流程回答下列问题：

（1）重晶石的化学式为_____，锌钡白可用于调制_____色和浅色油漆。

（2）处理过程的步骤为：①__________；②洗涤；③__________。

（3）设备1是冷却分离塔，若设备1前面的导气管过长、过窄，可能使导气管堵塞，其原因是____________________。

（4）检验锌钡白中含有S^2-的方法是__________。

（5）设备2中所用的洗涤剂是NaOH溶液，则y的化学式为__________。写出设备2中发生反应的离子方程式：_______________、_______________。

（6）可用_____法分离设备2溶液中的钠盐，进行分离前，需要查得的是__________。

（7）制备过程中得到的硫磺，除了可用来制硫酸外，其它的用途为__________（至少写一种）。

阅读下列材料：

材料一：国家 * * 胡 * * 在中央民族工作会议暨国务院第四次全国民族团结进步表彰大会上强调，新世纪新阶段的民族工作必须把各民族共同奋斗、共同繁荣发展作为主题。

材料二：《中国的民族区域自治》白皮书指出，坚持和完善民族区域自治，充分发挥制度优势，不断提高民族地区的经济和社会发展水平，是新世纪中国全面建设小康社会所要着力解决的问题。

请回答：

（1）结合我们要构建的和谐社会，谈谈你对“共同团结奋斗，共同繁荣发展”这个民族工作的主题的理解。

________________________________________________________________________________________________________________________________________________________________________________________

（2）我国为什么要坚持和完善民族区域自治制度？

________________________________________________________________________________________________________________________________________________________________________________________

关于心电图产生原理的表述，不正确的是（）

A.除极和复极过程中，任何一部分的心肌纤维都会产生一定数量的电偶并形成一定的向量

B.心脏在除极和复极的任一瞬间，不同部位的心肌可出现无数对电偶，产生无数方向不同、大小不等的心电向量

C.某一瞬间心电向量的总和，称为瞬间综合心电向量

D.探查电极在体表某部位记录到的心电变化实际上是多个瞬间的综合向量

E.某一瞬间各处心肌的除极向量大小和方向是相同的