Một quả bóng có khối lượng 500 g đang nằm yên trên mặt đất thì bị một cầu thủ đá bằng một lực 250 N. Bỏ qua mọi ma sát. Gia tốc mà quả bóng thu được là

A.  2   m / s 2

B.  0 , 002   m / s 2

C. 0 , 5   m / s 2

D. 500   m / s 2

X là este no, đa chức, mạch hở; Y là este ba chức, mạch hở (được tạo bởi glixerol và một axit cacboxylic đơn chức, không no chứa một liên kết C=C). Đốt cháy hoàn toàn 17,02 gam hỗn hợp E chứa X, Y thu được 18,144 lít CO₂ (đktc). Mặt khác, đun nóng 0,12 mol E cần dùng 570 ml dung dịch NaOH 0,5M thu được dung dịch G. Cô cạn dung dịch G thu được hỗn hợp T chứa 3 muối (T₁, T₂, T₃) và hỗn hợp 2 ancol có cùng số nguyên tử cacbon. Biết M_T1 < M_T2 < M_T3 và T₃ nhiều hơn T₁ là 2 nguyên tử cacbon. Phần trăm khối lượng của T₃ trong hỗn hợp T gần nhất với giá trị nào dưới đây? 

A. 25%.         

B. 30%.         

C. 20%.         

D. 29%.

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

Not so long ago almost any students who successfully completed a university degree or diploma course could find a good career quite easily. Companies toured the academic institutions, competing with each other to recruit graduates. However, those days are gone, even in Hong Kong, and nowadays graduates often face strong competition in the search for jobs.

Most careers organization highlight three stages for graduates to follow in the process of securing a suitable career: recognizing abilities, matching these to available vacancies and presenting them well to prospective employers

Job seekers have to make a careful assessment of their own abilities. One area of assessment should be of their academic qualifications, which would include special skills within their subject area. Graduates should also consider their own personal values and attitudes, or the relative importance to themselves of such matters as money, security, leadership and caring or others. An honest assessment of personal interests and abilities such as creative or scientific skills acquired from work experience should also be give careful thought

The second stage is to study the opportunities available for employment and to think about how the general employment situation is likely to develop in the future. To do this, graduates can study job vacancies and information in newspapers or the can visit a career office, write to possible employers for information or contact friends or relatives who may already be involved in a particular profession. After studying all various options, they should be in a position to make informed comparisons between various careers

Good personal presentation is essential in the search for a good career. Job application forms and letters should, of course, be filled in carefully and correctly, without grammar or spelling errors. Where additional information is asked for, job seekers should describe their abilities and work experience in more depth, with example if possible. They should try to balance their own abilities with the employer’s needs, explain why they are interested in a career with the particular company and try to show that they already know something about the company and its activities

When graduates are asked to attend for the interview, they should prepare properly by finding out all they can about the prospective employer. Dressing suitably and arriving for the interview on time are also obviously important. Interviewees should try to give positive and helpful answers and should not be afraid to ask questions about anything they are unsure about. This is much better than pretending to understand a question and giving an unsuitable answer

There will always be good career opportunities for people with ability, skills, and determination; the secret to securing a good job is to be one of them

In paragraph 6, the writer seems to suggest that ____

A. interviewees should ask question if they can’t think of an answer

B. pretending to understand a question is better than giving a suitable answer

C. it is better for interviewees to be honest than to pretend to understand

D. it is not a good idea for interviewees to be completely honest in their answers

Read the following passage and mark the letter A, B, C or D on you answer sheet to indicate the correct answer to each of the questions

When jazz began to lose its reputation as “low-down” music and to gain well-deserved acclaim among intellectuals, musicians began to feature many instruments previously considered inappropriate for jazz. Whereas before the 1950s, jazz musicians played only eight basic instruments in strict tempo, in this decade they started to improvise on the flute, electric organ, piccolo, accordion, cello, and even bagpipes, with the rhythm section composed for strings or piano. Big bands no longer dominated jazz, and most changes emerged from small combos, such as the Dave Brubeck Quartet and the Gerry Mulligan Quartet. The Gerry Mulligan Quartet proved that a small, modern band could sound complete without a piano; the rhythm section consisted only of a set of drums and a string bass.

Jazz continued to move in new directions during the 1960s. Saxophonist and composer Ornette Coleman led a quartet playing “free” jazz that was atonal. Pianist Cecil Taylor also conducted similar experiments with music, and John Coltrane included melodies from India in his compositions. In the 1970s, musicians blended jazz and rock music into fusion jazz which combined the melodies and the improvisations of jazz with the rhythmic qualities of rock ‘n’ roll, with three or five beats to the bar and in other meter. The form of jazz music was greatly affected by electric instruments and electronic implements to intensify, distort, or amplify their sounds. However, the younger musicians of the time felt compelled to include a steady, swinging rhythm which they saw as a permanent and essential element in great jazz.

The author of the passage implies that in the 1950s, jazz musicians _______

A. strictly adhered to its traditions and compositions

B. probably continued with its tempo and instrumentation

C. experimented with rhythm and instrument

D. increased the tempo to keep up with the changes

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 55 to 64

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

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

A. will damage areas outside of the localized regions

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

C. will react harmfully with natural pollutants

D. can overwhelm the natural system that removes pollutants

Kim loại nào sau đây tan được trong cả dung dịch NaOH và dung dịch HCl

A.  Al.

B.  Fe.

C. Cr.

D. Cả Cr và Al.

Mark the letter A, B, C, or D on your answer sheet to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.

A. snatched 

B. laughed  

C. introduced 

D. involved

Cho este X có công thức phân tử là C₄H₈O₂ tác dụng với NaOH đun nóng thu được muối Y có phân tử khối lớn hơn phân tử khối của X. Tên gọi của X là :

A. metyl propionat.

B. etyl axetat

C. isopropyl fomat

D. propyl fomat

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 11 to 20.
          All relationships go through difficult times. In the past, when married couples had problems they usually didn’t (11) _________. They had to either (12)_________ with each other or continue to live together in an unhappy relationship. Getting divorced wasn’t an option for most people due to economic and social reasons. Some people believe that this wasn’t such a bad thing. They say that relationships require hard work and (13)_________ . “If a relationship is going to last a lifetime, you have to keep working at it,” says Doreen, who is celebrating her fiftieth wedding anniversary this year. “It isn’t all roses and romance. (14)_________ perfect all of the time.

These days young people give up when there’s the (15)_________ argument.” Experts agree that communication is key. The most important thing is to (16) _________talking. How many times have you heard yourself say to (17)_________ , “If only you’d listen!” or “ I wish you (18)_________ do that!” The truth is, the (19)_________ couples talk, the better their relationship (20) _________be.
Điền vào ô 12

A. get on             

B. go out              

C. get back           

D. fall out