Cho các phản ứng sau:

4HCl + M n O 2 → M n C l 2 + C l 2 + 2 H 2 O

2HCl + Fe → F e C l 2 + H 2

3HCl + F e O H 3 → F e C l 3 + 3 H 2 O

6HCl + 2Al → 2 A l C l 3 + 3 H 2

16HCl + 2 K M n O 4 → 2KCl + 2 M n C l 2 + 5 C l 2 + 8 H 2 O

Số phản ứng trong đó HCl thể hiện tính oxi hóa là

A. 2

B. 1

C. 4

D. 3

Read the following passage and mark the letter A, B, C or D to indicate the correct answer.

The Nobel Peace Prize is awarded annually and the first woman to win this prize was Baroness Bertha Felicie Sophie von Suttner in 1905. In fact, her work inspired the creation of the Prize. The first American woman to win this prize was Jane Addams, in 1931. However, Addams is best known as the founder of Hull House.

Jane Addams was born in 1860, into a wealthy family. She was one of a small number of women in her generation to graduate from college. Her commitment to improving the lives of those around her led her to work for social reform and world peace. In the 1880s Jane Addams traveled to Europe. While she was in London, she visited a ‘settlement house’ called Toynbee Hall. Inspired by Toynbee Hall, Addams and her friend, Ellen Gates Starr, opened Hull House in a neighborhood of slums in Chicago in 1899. Hull House provided a day care center for children of working mothers, a community kitchen, and visiting nurses. Addams and her staff gave classes in English literacy, art, and other subjects. Hull House also became a meeting place for clubs and labor unions. Most of the people who worked with Addams in Hull House were well educated, middle-class women. Hull House gave them an opportunity to use their education and it provided a training ground for careers in social work.

Before World War I, Addams was probably the most beloved woman in America. In a newspaper poll that asked, “Who among our contemporaries are of the most value to the community?”, Jane Addams was rated second, after Thomas Edison. When she opposed America’s involvement in World War I, however, newspaper editors called her a traitor and a fool, but she never changed her mind. Jane Addams was a strong champion of several other causes. Until 1920, American women could not vote. Addams joined in the movement for women’s suffrage and was a vice president of the National American Woman Suffrage Association. She was a founding member of the National Association for the Advancement of Colored People (NAACP), and was president of the Women’s International League for Peace and Freedom. . Her reputation was gradually restored during the last years of her life. She died of cancer in 1935.

With which of the following subjects is the passage mainly concerned?

A. The first award of the Nobel Peace Prize to an American woman 

B. A woman’s work for social reform and world peace

C. The early development of Social Work in America

D. Contributions of educated women to American society

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

        An air pollutant is defined as a compound added directly or indirectly by humans to the atmosphere in such quantities as to affect humans, animals, vegetation, or materials adversely. Air pollution requires a very flexible definition that permits continuous changes. When the first air pollution laws were established in England in the fourteenth century, air pollutants were limited to compounds that could be seen or smelled - a far cry from the extensive list of harmful substances known today. As technology has developed and knowledge of the health aspects of various chemicals has increased, the list of air pollutants has lengthened. In the future, even water vapor might be considered an air pollutant under certain conditions.

        Many of more important air pollutants, such as sulfur oxides, carbon monoxides and nitrogen oxides are found in nature. As the Earth developed, the concentration of these pollutants was altered by various chemical reactions; they became components in biogeochemical cycles. These serve as an air purification scheme by allowing the compounds to move from the air to the water or soil. On a global basis, nature's output of these compounds dwarfs that resulting from human activities.

        However, human production usually occurs in a localized area, such as a city. In such a region, human output may be dominant and may temporarily overload the natural purification scheme of the cycles. The result is an concentration of noxious chemicals in the air. The concentrations at which the adverse effects appear will be greater than the concentrations that the pollutants would have in the absence of human activities. The actual concentration need not be large for a substance to be a pollutant; in fact, the numerical value tells us little until we know how much of an increase this represents over the concentration that would occur naturally in the area. For example, sulfur dioxide has detectable health effects at 0. 08 parts per million (ppm), which is about 400 times its natural level. Carbon monoxide, however has a natural level of 0. 1 ppm and is not usually a pollutant until its level reaches about 15 ppm.

The word “localized” in the third paragraph is closest in meaning to .

A. surrounded

B. encircled

C. specified

D. circled

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

        An air pollutant is defined as a compound added directly or indirectly by humans to the atmosphere in such quantities as to affect humans, animals, vegetation, or materials adversely. Air pollution requires a very flexible definition that permits continuous changes. When the first air pollution laws were established in England in the fourteenth century, air pollutants were limited to compounds that could be seen or smelled - a far cry from the extensive list of harmful substances known today. As technology has developed and knowledge of the health aspects of various chemicals has increased, the list of air pollutants has lengthened. In the future, even water vapor might be considered an air pollutant under certain conditions.

        Many of more important air pollutants, such as sulfur oxides, carbon monoxides and nitrogen oxides are found in nature. As the Earth developed, the concentration of these pollutants was altered by various chemical reactions; they became components in biogeochemical cycles. These serve as an air purification scheme by allowing the compounds to move from the air to the water or soil. On a global basis, nature's output of these compounds dwarfs that resulting from human activities.

        However, human production usually occurs in a localized area, such as a city. In such a region, human output may be dominant and may temporarily overload the natural purification scheme of the cycles. The result is an concentration of noxious chemicals in the air. The concentrations at which the adverse effects appear will be greater than the concentrations that the pollutants would have in the absence of human activities. The actual concentration need not be large for a substance to be a pollutant; in fact, the numerical value tells us little until we know how much of an increase this represents over the concentration that would occur naturally in the area. For example, sulfur dioxide has detectable health effects at 0. 08 parts per million (ppm), which is about 400 times its natural level. Carbon monoxide, however has a natural level of 0. 1 ppm and is not usually a pollutant until its level reaches about 15 ppm.

It can be inferred from the first paragraph that ______.

A. the definition of air pollution will continue to change. 

B. Most air pollutants today can be seen or smelled. 

C. a substance becomes an air pollutant only in cities. 

D. water vapor is an air pollutant in localized areas.