Cho đường tròn (O; R) và dây cung BC = R. Hai tiếp tuyến của đường tròn (O) tại B, C cắt nhau ở A. Tính: A B C ^ , B A C ^

Cho đường tròn tâm O, đường kính AB. Lấy điểm P khác A và B trên đường tròn. Gọi T là giao điểm của AP với tiếp tuyến tại B của đường tròn. Chứng minh

A P O ^ = P B T ^

Amelia Earhart, the first woman to fly solo across the Atlantic, disappeared on June 1937 while attempting to fly around the world

A. to fly                

B. the Atlantic               

C. on                    

D. attempting

Read the following passage carefully and then choose the best answer to  each question.

During the seventeenth and eighteenth centuries, almost nothing was written about the contributions of women during the colonial period and the early history of the newly formed United States. Lacking the right to vote and absent from the seats of power, women were not considered an important force in history. Anne Bradstreet wrote some significant poetry in the seventeenth century, Mercy Otis Warren produced the best contemporary history of the American Revolution, and Abigail Adams penned important letters showing she exercised great political influence over her husband, John, the second President of the United States. But little or no notice was taken of these contributions. During these centuries, women remained invisible in history books.

Throughout the nineteenth century, this lack of visibility continued, despite the efforts of female authors writing about women. These writers, like most of their male counterparts, were amateur historians. Their writings were celebratory in nature, and they were uncritical in their selection and use of sources.

During the nineteenth century, however, certain feminists showed a keen sense of history by keeping records of activities in which women were engaged. National, regional, and local women’s organizations compiled accounts of their doings. Personal correspondence, newspaper clippings, and souvenirs were saved and stored. These sources from the core of the two greatest collections of women’s history in the United States one at the Elizabeth and Arthur Schlesinger Library at Radcliffe College, and the other the Sophia Smith Collection at Smith College. Such sources have provided valuable materials for later Generations of historians.

Despite the gathering of more information about ordinary women during the nineteenth Century, most of the writing about women conformed to the “great women” theory of History, just as much of mainstream American history concentrated on “great men.” To demonstrate that women were making significant contributions to American life, female authors singled out women leaders and wrote biographies, or else important women produced their autobiographies. Most of these leaders were involved in public life as reformers, activists working for women’s right to vote, or authors, and were not representative at all of the great of ordinary woman. The lives of ordinary people continued, generally, to be untold in the American histories being published. 

The word “contemporary” in the 1^st paragraph means that the history was___________.

A. informative

B. thoughtful

C. written at that time

D. faultfinding

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 question below.

Why is it that many teenagers have the energy to play computer games until late at night but can’t find the energy to get out of bed (35) ________ for school? According to a new report, today’s generation of children are in danger of getting so (36)_______ sleep that they are putting their mental and physical health at (37)_______. Adults can easily survive on seven to eight hours’ sleep a night, (38)_______teenagers require nine or ten hours. According to medical experts, one in five youngsters (39)________ anything between two and five hours’ sleep a night less than their parents did at their age. This (40) _____ serious questions about whether lack of sleep is affecting children’s ability to concentrate at school. The connection between sleep deprivation and lapses in memory, impaired reaction time and poor concentration is well (41) _______. Research has shown that losing as little as half an hour’s sleep a night can have profound effects (42) ______how children perform the next day. A good night’s sleep is also crucial for teenagers because it is while they are asleep (43)______ they release a hormone that is essential for their ‘growth spurt’ (the period during teenage years when the body grows at a rapid rate). It’s true that they can, to some (44) ______, catch up on sleep at weekends, but that won’t help them when they are dropping off to sleep in class on a Friday afternoon. By Tim Falla and Paul A.Davies, Solutions Advanced. OUP

Điền vào ô 38

A. whereas

B. or

C. because

D. So

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  45 to 54.

A survey is a study, generally in the form of an interview or a questionnaire, which provides information concerning how people think and act. In the United States, the best-known surveys are the Gallup poll and the Harris poll. As anyone who watches the news during campaigns presidential knows, these polls have become an important part of political life in the United States.

North Americans are familiar with the many “person on the street” interviews on local television news shows. While such interviews can be highly entertaining, they are not necessarily an accurate indication of public opinion. First, they reflect the opinions of only those people who appear at a certain location. Thus, such samples can be biased in favor of commuters, middle-class shoppers, or factory workers, depending on which area the news people select. Second, television interviews tend to attract outgoing people who are willing to appear on the air, while they frighten away others who may feel intimidated by a camera. A survey must be based on a precise, representative sampling if it is to genuinely reflect a broad range of the population.

In preparing to conduct a survey, sociologists must exercise great care in the wording of questions. An effective survey question must be simple and clear enough for people to understand it. It must also be specific enough so that there are no problems in interpreting the results. Even questions that are less structured must be carefully phrased in order to elicit the type of information desired. Surveys can be indispensable sources of information, but only if the sampling is done properly and the questions are worded accurately.

There are two main forms of surveys: the interview and the questionnaire. Each of these forms of survey research has its advantages. An interviewer can obtain a high response rate because people find it more difficult to turn down a personal request for an interview than to throw away a written questionnaire. In addition, an interviewer can go beyond written questions and probe for a subject’s underlying feelings and reasons. However, questionnaires have the advantage of being cheaper and  more consistent

It can be inferred from the passage that one reason that sociologists may become frustrated with questionnaires is that

A. respondents are too eager to supplement questions with their own opinions

B. respondents often do not complete and return questionnaires

C. questionnaires are expensive and difficult to distribute

D. questionnaires are often difficult to read

Mark the letter A, B, C or D on your answer sheet to to indicate the word that differs from the other three in the position of primary stress in each of the following question.

A. economics       

B. occupation       

C. sentimental      

D. traditional 

Tại sao phải quy định thống nhất tần số của dòng điện xoay chiều tạo ra trong kĩ thuật?

Last Sunday, Texas-based game-fans The Speed Gamers _____ in a charity activity to donate money to relief organisations.

A. have participated

B. participated 

C. had participated 

D. were participating