（9分）将一块重12.9 g且表面已经氧化的铝片放入300 mL 3 mol/L

分析比较物质在组成、性质等方面的异同，可为物质的分离和鉴别提供依据．

（1）从组成上看，BaCl₂、NaCl都含有______元素，但BaSO₄不含有；

（2）将BaSO₄、BaCl₂、NaCl三种固体组成的混合物溶于足量的水后，充分搅拌后过滤，留在滤纸上的固体是______；

（3）根据BaCl₂溶液和NaCl溶液中的金属离子不同，可用稀硫酸将NaCl溶液和BaCl₂溶液鉴别开．请写出稀硫酸和BaCl₂反应的化学方程式______；

（4）按如下方案分离BaCl₂和NaCl的固体混合物时，X溶液中溶质是______．

A．K₂CO₃      B．Na₂CO₃     C． Na₂SO₄

．

Accidents happen, but when they destroy the delicate balance of nature and cause the whole world to suffer, they become disasters, and we  should do all we can to prevent them from happening again.

Bhopal chemical leak, December 1984, Bhopal, India

An explosion in the Union Carbide chemical plant in Bhopal, India, released a deadly gas called methyl (甲基) isocyanate(异氰盐酸), which is used to make pesticides. The gas formed a cloud that killed 2500 people; another 50000- 100000 people became ill. Trees and plants in the area became yellow and brittle. The explosion was caused by a mechanical failure that was not noticed in time to stop it.

Exxon Valdez oil spill, March 1989, Alaska, U.S.

On March 24, 1989, 11 million gallons of crude oil spilled into Prince William Sound from the tanker Exxon Valdez when its hull hit a reef and tore open. The oil, which is not yet cleaned up after billions of dollars have been spent and the millions of birds, fish, and other wildlife have died, was caused by human error and could have been avoided.

Chernobyl, April 1986, USSR

At 1:23 A.M. on Saturday, April 26, 1986, the reactor blew at nuclear power plant in Chernobyl, ripping open the core, blowing the roof off the building, starting more than 30 fires, and allowing radioactive material to leak into the air. Some 31 people were killed and 200 people were treated for radiation poisoning. Still at risk are 135000 people from the 179 villages within 20 miles, of the plant who were exposed to the radiation before being evacuated. Glaring violations of safety rules were at the bottom of this tragic event.

Love Canal, 1953, New York, U.S.

Love Canal, a small town in upstate New York near Niagara Falls, was destroyed by waste from chemical plants. Beginning in 1947, chemical companies could legally dump their waste products into the canal. The area developed a foul smell, trees lost their bark, and leaves fell throughout the year. A health survey found that the drinking water contained excessive levels of 82 industrial chemicals, 7 of which were thought to cause cancer. The people of Love Canal had an unusually high rate of cancer and birth defects. Eventually, many of the houses had to be abandoned. Today, the town has been partly cleaned up and some families have moved back to the area.

Three Mile Island, 1979, Pennsylvania, U.S.

On March 28, 1979, the worst accident in U.S. nuclear reactor history occurred at the Three Mile Island power station, near Harrisburg, Pennsylvania. No one was killed, and very little radioactivity was released into the air when coolant (the fluid that keeps a machine cool) escaped from the reactor core due to a combination of mechanical failure and human error. After 10 years and $ 1 billion in cleanup costs, the lower extremes of the reactor are still so radioactive that workers must use remote - control equipment to remove the remaining fragment of fuel core.

小题1:This passage mainly discusses_______.

A．accidents that affected many living things

B．air pollution

C．water pollution

D．what people are doing to prevent environmental disasters小题2:You can infer from the passage that the Bhopal Chemical leak_______.

A．happen at night

B．was the worst accident in the history of India

C．caused more deaths than sicknesses

D．could have been avoided小题3: It can be inferred from the passage that the people in Love Canal_______.

A．didn’t know that chemical companies were dumping waste products into the canal

B．didn’t know that their water was becoming dangerous to drink

C．tried to stop companies from dumping their waste products into the canal

D．didn’t mind that chemical companies were dumping waste products into the canal小题4:The best title for the article is ________.                                                                       A. Accidents in Some Countries    B. Disasters in Some Countries

C. Our Earth Is Out of Control         D How to Prevent Accidents from Happening Again

有关系模式A(C，T，H，R，S)，其中各属性的含义是：C：课程T：教员H：上课时间R：教室S：学生根据语义有如下函数依赖集：F={C→T，(H，R)→C，(H，T)→R，(H，S)→R}现将关系模式A分解为两个关系模式A1(C，T)和A2(H，R，S)，则其中A1的规范化程度达到（ ）。

A．1NF

B．2NF

C．3NF

D．BCNF

患者女性，68岁，农民，因“突发意识障碍2小时”急诊入院。2小时前其家人发现意识不清，呼之不应，卧床，身周见呕吐物，无抽搐，无排尿、粪失禁。既往有高血压病史。查体：体温38.3℃，心率93次/分，呼吸20次/分，血压198/135mHg（1mmHg=0.133kPa），浅昏迷，左侧瞳孔散大，光反射消失，右侧肢体偏瘫，右侧巴宾斯基征（+）。

提示：拟手术治疗。针对该脑出血患者，常用的外科治疗手术方法有（）

A.骨瓣开颅血肿清除术

B.小骨窗开颅血肿清除术

C.锥颅穿刺血肿清除术

D.腰大池置管持续引流术

E.立体定向血肿清除术

F.脑室外引流术

G.颞肌下减压术

效率工资理论认为，在资本要素不变的情况下，企业的产出过程中投入的劳动要素量和工人的努力程度取决于（）

A.实际工资

B.名义工资

C.监督程度

D.劳动力的供求程度