解方程x+3x2-1+x2-1x+3=52时，设y=x+3x2-1，则原方程化成

从下图舞动的北京印中，你可获取的历史信息有 

①汉字的演变  ②篆刻艺术   ③书法艺术、绘画融为一体        

A．①②③

B．①③

C．①②

D．②③

关于加氢裂化开车方案应包含的主要内容，下列叙述错误的是（）。

A、设备吹扫及贯通试压工作

B、单机试运转工作

C、组织对装置的检修质量进行全面的验收工作

D、系统置换驱赶空气

下图是甲、乙、丙三名同学设计的验证铜和浓硝酸反应原理的装置

已知：2NO₂+2NaOH═NaNO₃+NaNO₂+H₂O

（1）写出铜和浓硝酸反应的离子反应方程式是______．

（2）和甲同学装置相比，乙同学设计的装置的优点是______、______．

（3）为了进一步验证NO₂和水的反应，某学生设计了丙装置．

先关闭弹簧夹______（填a或b或c），再打开弹簧夹______和______（填a或b或c），才能使NO₂气体充满②试管．

（4）当气体充满②试管后，将铜丝提起与溶液脱离，欲使烧杯中的水进入②试管．应如何操作______．

（5）某位同学的实验中未得到蓝色的溶液，而呈绿色，他分析可能是生成的部分NO₂溶解在溶液中造成的．请你帮他设计简单实验方案验证他的推测．

PART THREE  READING COMPREHENSION ( 30 points)

Directions: Read the following three passages. Each passage is followed by several questions or unfinished statements. For each of them there are four choices marked A, B, C and D. Choose the one that fits best according to the information given in the passage.

When Christopher Columbus landed on the then unnamed Costa Rica in 1502, he saw many Indians wearing gold earrings. So he thought the land must be rich in gold. He named the place Costa Rica, which means “rich coast” in Spanish.

Though little gold was found, Costa Rica today is indeed rich with coffee and bananas. Coffee is the most important product in Costa Rica and most of it is exported (出口) to other countries like America and West Germany. Bananas are the country’s second most important export.

Costa Ricans also grow many other crops such as fruits, corn and beans for their own use. Costa Ricans love colors and their houses are painted in bright colors.

Education is very important to the Costa Ricans. Almost every village has a school and education is a must for children between seven and fourteen years of age. Boys and girls go to separate (单独的) schools. Classes begin in March and end in November. The other three months of the year are harvest time and the children have to help their parents to pick coffee beans.

56. What’s the main idea of the first paragraph?

A. How Columbus found Costa Rica.              B. How Costa Rica got its name.

C. What the Costa Ricans wore.                 D. What language the Costa Ricans spoke.

57. The Costa Ricans may NOT paint their houses ______.

A. pink and red                              B. grey and black

C. blue and green                            D. yellow and orange

58. In Costa Rica, boys and girls between seven and fourteen ______.

A. must go to school                         B. study in the same school

C. do not have to go to school at all            D. can choose to stop schooling at any time

59. From December to February, school children in Costa Rica ______.

A. have lessons every day                     B. have their examinations

C. help their parents pick coffee beans          D. help their parents decorate their houses

60. This passage is mainly about ______.

A. Christopher Columbus                    B. Costa Rica 

C. some products from Costa Rica             D. the education of Costa Rica

社会工作者对服务对象说：“我不知道我是否误会了你的意思，你上次一再告诉我，你很为自己的成就自豪，但刚才从你的谈话中，我感到你对自己很不满意。你对自己的看法到底是怎样的呢？”社会工作者运用的个案工作技巧是（）。

A.澄清

B.自我披露

C.摘要

D.对质