海岸线长度为（）万千米。A、1.5 B、1.8 C、2 D、2.3

把3a³-5和a²b+ab²+1按某种标准进行分类时属于同一类，则下列哪一个多项式也属于此类[ ]

A．-a⁵-b⁵

B．4x²-7

C．xyz-1

D．a²+2ab+b²

阅读理解。

     Two hours from the tall buildings of Manhattan and Philadelphia live some of the world's largest black

bears. They are in northern Pennsylvania's Pocono Mountains, a home they share with an abundance of

other wildlife.

     The streams, lakes, meadows, mountain ridges and forests that make the Poconos an ideal place for

black bears,have also attracted more people to the region. Open spaces are threatened by plans for housing

estates and important habitats are endangered by highway construction. To protect the Poconos' natural

beauty from irresponsible development, the Nature Conservancy (大自然保护协会) named the area one

of America's "Last Great Places"

     Operating out of a century-old schoolhouse in the village of Long Pond, Pennsylvania, the

conservancy's bud Cook is working with local people and business leaders to balance economic growth

with environmental protection. By forging partnerships with people like Francis Altemose, the Conservancy

has been able to protect more than 14,000 acres of environmentally important land in the area.

      Altemose's family has farmed in the Pocono area for generations. Two years ago Francis worked with

the Conservancy to include his farm in a county farmland protection program. As a result, his family's land

can be protected from development and the Altemoses will be better able to provide a secure financial future

for their 7-year-old grandson. Cook attributes the Conservancy's success in the Poconos to having a local

presence and a commitment to working with local residents

      "The key to protecting these remarkable lands is connecting with the local community," Cook said. "The

people who live there respect the land. They value quite forests, clear streams and abundant wildlife. They are

eager to help with conservation effort. For more information on how you can help The Nature Conservancy

protect the Poconos and the world's other"Last Great Places," please call 1-888-564 6864, or visit us on the

World Wide Web at www.tnc.org.

1. The purpose in naming the Poconos as one of America's " Last Great Places" is to ________.

A. gain support from the local community

B. protect it from irresponsible development

C. make it a better home for black bears

D. provide financial security for future generations

2. We learn from the passage that _______.

A. the population in the Pocono area is growing

B. wildlife in the Pocono area is dying out rapidly

C. the security of the Pocono residents is being threatened

D. farmlands in the Pocono area are shrinking fast

3. What is important in protecting the Poconos according to Cook?

A. The setting up of an environmental protection website

B. Support from organizations like The Nature Conservancy

C. Cooperation with the local residents and business leaders

D. Inclusion of farmlands in the region's protection program

4. The passage most probably is ________.

A. an official document

B. a news story

C. an advertisement

D. a research report

海带含有丰富的碘．为了从海带中提取碘，某研究性学习小组设计并进行了以下实验：

请填写下列空白：

（1）步骤①灼烧海带时，除需要三角架外，还需要用到的仪器是______（从下列仪器中选择所需的仪器，用标号字母填写在空白处）

A、烧杯  B、坩埚  C、表面皿  D、泥三角  E、酒精灯  F、干燥器

（2）步骤③的实验操作名称是______；步骤⑥的目的是从含碘苯溶液中分离出碘和回收苯，该步骤的实验操作名称是______．

（3）步骤⑤中，某学生选择用苯来提取碘的理由是______．

（4）请设计一种检验提取碘后的水溶液中是否还含有单质碘的简单方法______．

一则好的广告必须有好的主题，而好的主题大多数来源于对于（）的主题进行分析，选择最佳角度确立主题。

A.目标专一

B.唯一角度

C.消费者需求

D.各种角度

牺牲阳极输出电流的大小与（）有关。

A、牺牲阳极有效电位差

B、填包料

C、阳极地床透气性

D、阴极保护电流