Mark the letter A, B, C, or D on your answer sheet to indicate the word CLOSEST in meaning to the underlined word in each of the following questions.

E-cash cards are the main means of all transactions in a cashless society.

A. cash-starved 

B. cash-strapped 

C. cash-in-hand 

D. cash-free 

Hai điện tích điểm  q 1 = 9 . 10 - 8 C   ;   q 2 = - 9 . 10 - 8 C đặt tại hai điểm A,B trong không khí cách nhau 25cm. Cường độ điện trường tại điểm M có AM=15cm ; BM=20cm là

A. 36000 V/m        

B. 41304,5 V/m       

C. 20250 V/m      

D. 56250 V/m

Đúng bài này quá hay
 

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 inEngland 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.

According to the passage, human-generated air pollution in localized regions _______.

A. will damage areas outside of the localized regions 

B. will react harmfully with natural pollutants

C. can be dwarfed by nature's output of pollutants

D. can overwhelm the natural system that removes pollutants

Hỗn hợp X gồm CaC₂ x mol và Al₄C₃ y mol. Cho một lượng nhỏ X vào H₂O rất dư, thu được dung dịch Y, hỗn hợp khí Z và a gam kết tủa Al(OH)₃. Đốt cháy hết Z, rồi cho toàn bộ sản phẩm vào Y được a gam kết tủa. Biết các phản ứng đều xảy ra hoàn toàn. Tỉ lệ x : y bằng

A. 1:3.

B. 2 : 1.

C. 1:2

D. 1 : 1.

Choose one of the given options which is incorrect

The more regularly you practice, the best appetite you get

A. The more regularly

B. practice

C. the best

D. get

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 35 to 42.

The United States Department of Education describes “giftedness” as exceptionally advanced performance or the potential for outstanding performance in intellectual, creative leadership, artistic, or specific academic fields. Children who demonstrate outstanding talents come from all social, cultural, and economic groups.

Educators believe that gifted students require special education services because their learning needs differ significantly from those of the general population. They learn more rapidly and are able to understand more abstract and complex ideas. They are also able to transform existing knowledge into new and useful forms, and to create new knowledge recognized for its originality, complexity, and elegance. Special education services and facilities for gifted children may enhance these abilities. In addition, some gifted learners may require special counseling services to address social or emotional adjustment issues that are complicated by their exceptional abilities.

Many regular elementary and secondary schools in the United States offer special programs designed specifically to meet the needs of gifted students. Some schools provide specialized education programs to gifted children exclusively. These schools offer advanced education in mathematics, science, technology, the arts, or other academic disciplines. Many schools rely on intelligence tests to identify gifted students. However, most guidelines for determining giftedness recommend the use of a combination of standardized test scores, rating systems developed by individual schools, classroom observation records, and performance assessments.

Gifted children may study a specially modified curriculum or may progress through academic subjects at an accelerated pace. Acceleration involves adapting education programs so that students may progress through particular subject material quicker than usual. These modifications may take place within the regular classroom setting or they may involve changing the child’s placement in school. Some gifted children gain early entrance to kindergarten, skip grades, enter college earlier than usual, or take specific courses with older children. Ideal programs for gifted students consider the individual needs of children and offer multiple options for services. These programs generally involve both advanced course materials and acceleration.

In order to help gifted children, some schools ___________.

A. provide them with coaching 

B. give them exclusive programs 

C. isolate them from the rest 

D. provide them with international programs

Thể đa bội là gì? Cho thí dụ.