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.
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 change. 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 the more important air pollutants, such as sulfur oxides, carbon monoxide, 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 increased 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 "adversely" in the first paragraph is closest in meaning to _________ .
A. negatively
B. admittedly
C. considerably
D. quickly
Giải bởi qa.haylamdo.com
Đáp án A
“Adversely” = “negatively”: một cách có hại, không tốt
Mark the letter A, b, C, or D to identify the underlined part that is not correct.
The doctor advised him (A) to avoid eating(B) fatty foods, having(C) more vegetables and drink much (D) water.
There were two small rooms in the beach house, _____ served as a kitchen
Mark the letter A, B, C, or D on your answer sheet to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions.
The ASEAN Para-Games are hosted by the same country where the SEA Games took place.
Mark the letter A, B, C, or D on your answer sheet to indicate the word(s) OPPOSITE in meaning to the underlined word(s) in each of the following questions.
Schooling is compulsory for all Vietnamese children from the age of 6 to 14.
Mark the letter A, B, C, or D on your answer sheet to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions.
Magma is the primary source of all the earth’s rocks.
After having used the new technique, the factory produced ____ cars in 2014 as the year before.
Mark the letter A, b, C, or D to identify the underlined part that is not correct.
Since poaching (A) is becoming more seriously(B) , the government has imposed stricter (C) laws to prevent it(D) .
