The students stay _____ home _____ Sunda

实验室用50mL0.50mol•L^-1盐酸、50mL0.55mol•L^-1NaOH，利用如图装置进行中和热的测定，请回答下列问题：

（1）不能用铜丝搅拌棒代替环形玻璃搅拌棒的理由是______．

（2）如用0.50mol•L^-1盐酸与NaOH固体进行实验，则实验中测得的“中和热”数值将______（填“偏大”、“偏小”、“不变”）

（3）实验得到表中的数据：

实验次数	起始温度t1/℃		终止温度t2/℃
	盐酸	NaOH溶液
1	20.2	20.3	23.7
2	20.3	20.5	23.8
3	21.5	21.6	24.9

经数据处理，t₂-t₁=3.4℃．则该实验测得的中和热△H=______

[盐酸和NaOH溶液的密度按1g•cm^-3计算，反应后混合溶液的比热容（c）按4.18J•（g•℃）^-1计算]．

情景选择。根据对话情景，从每题所给的三个选项（A、B和C）中，选出最佳选项。

小题1:— I am sorry I lost your pen.

— _______

A. It doesn’t matter, I have another one.  

B. You should buy me a new one.

C. Be more careful next time.

小题2: — Would you like to go for a picnic with us this weekend?

— _______

A. I don’t like it. B. Yes, I’d love to.   C. I don’t want to go.

小题3:— We are going on a visit to the Great Wall.

— _______

A. Have a good time.    B. Don’t waste time.   C. I am so sorry to hear that.

小题4:— Would you mind not opening the window?

— _______

A. Yes, please. B. I’m sorry about that.   C. No, I don’t.

小题5:— I’m worried about the coming exam.

— _______

A. That’s too bad.  B. What a shame.   C. Don’t be nervous.

一个正方形的边长增加6分米，面积增加36平方分米．______．

阅读理解

     Isaac Stern was more than a great violin player. He was one of the most honored musicians in the

world, an international cultural ambassador. And he was also a teacher and activist. For more than sixty

years, Mr. Stern performed excellent music. He performed in concerts around the world and on

recordings.

     Isaac Stern was born in 1920 in Ukraine. His parents moved to California the following year. He began

taking violin lessons after hearing a friend play the instrument. Later, he began studying music at the San

Francisco Conservatory(旧金山音乐学院). He progressed quickly. When he was sixteen, he played

with the San Francisco Symphony Orchestra. The next year, he performed in New York and was

praised by music critics.

     Isaac Stern became one of the busiest musicians of his day. He played more than one hundred

concerts a year. He also became one of the most recorded musicians in history. Isaac Stern also

supported artistic development and freedom.

     In 1979, Isaac Stern visited China. He met with Chinese musicians and students. He taught them

about classical Western music. His visit was made into a film. It is called From Mao to Mozart:Isaac

Stern in China. It won an Academy Award for best documentary film.

     In 1984, Isaac Stern received the Kennedy Center Honors Award for his gifts to American culture

through music. He expressed his thoughts about the part that music plays in life. He said music is an

important part of a civilized life. He said people need music as much as they need bread.

     Isaac Stern died in 2001 at the age of eighty-one. He was a major influence on music in the twentieth

century. He leaves the world richer with his many recordings.

1. What did Isaac Stern think of music?

A. Necessary.        

B. Difficult.

C. Entertaining.            

D. Interesting.

2. The passage mentioned Isaac Stern's visit to China mainly to ________.

A. encourage people to develop the international relationship

B. advise the readers to take up music

C. introduce more achievements of Isaac Stern

D. show he acted as an international cultural ambassador

3. Which of the following statements is TRUE about Isaac Stern?

A. He was born in California in the 1920s.

B. He had visited many countries to advertise his recordings.

C. He played less than one hundred concerts in all.

D. His excellent music life lasted over 60 years.

4. From the passage, we can infer that ________.

A. Isaac Stern influenced the culture in the 20th century a lot

B. Isaac Stern was one of the most active musicians of his day

C. Isaac Stern was so busy that he couldn't spare time to educate the youth

D. Isaac Stern led a rich life in his later life

5. What will be the best title for the passage?

A. Isaac Stern and the awards he got

B. Isaac Stern's life of pursuing music

C. Isaac Stern:one of the most honored musicians

D. Isaac Stern's visit to China

生命最基本和最普遍的特征是和 。