Cho tứ giác ABCD. Chứng minh rằng tứ giác đó là hình bình hành khi và chỉ khi 

Mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions.

If I _____ it was a formal party, I wouldn't have worn my old jeans and a jumper.

A. knew

B. could know

C. had been knowing

D. had known 

Nhiệt độ trong tủ lạnh rất lạnh khiến cho nước bị ngưng tụ lại và đông thành đá

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.

  The concept of being environmentally conscious, or “green”, has become more prevalent in twenty first-century U.S culture. It has begun to affect the manufacturing of everything from non-toxic household cleaning products to motor vehicles powered by alternative sources of energy. However, one way of being “green” that is perhaps not as apparent to the viewer but of equal importance in being environmentally conscious, is the construction of buildings that are considered “sustainable”. Sustainable buildings are those that do not impose on the environment or rely on the over-utilization of energy or natural resources. There are four main principles of sustainability, which includes consideration of the health and stability of all living things and their environmental diversity, as well as the economic opportunities of humanity.

  Sustainable architecture consists of environmentally conscious design techniques. In the past, the demolition of an old building meant that all or most of the debris of the building would end up in a landfill or a waste disposal site. Today, architects can plan and design a building that uses recycled materials, such as wood, concrete, stone, or metal. These materials are salvaged from the demolition of an older building and can be appropriately incorporated into a new construction. Architects and construction supervisors may also choose to recycle more organic parts of demolished buildings, such as wooden doors, windows and other glass, ceramics, paper, and textiles.

  A problem that has often arisen has been with how a site crew-whether it is demolition or construction crew determines and sorts what is “waste” and what is recyclable. Architects and environmental scientists have to decide whether or not a material is appropriate for use in new construction and how it will impact the environment. They must evaluate the materials from the demolition and determine what those materials contain, and if they meet the standards set by the U.S, government’s Environmental Protection Agency (the EPA). If the debris from the demolition contains hazardous materials that are harmful to the environment or to the consumer, such as asbestos, then the material is not salvageable. Use of the asbestos for insulation and as a form of fire retardation in buildings and fabrics was common in the nineteenth century. Asbestos was once used in shingles on the sides of buildings, as well as in the insulation in the interior walls of homes or other construction. In new “green” construction, insulation that once asbestos- based can be replaced with recycled denim or constructed with cellulose-a fibrous material found in paper products. The same-assessment applies to wood or wallboard painted with toxic lead-based paints. In addition, gas-flow regulators and meters on both water and gas heating systems constructed prior to 1961 must be carefully evaluated to determine that they do not contain dangerous substances such as mercury. Mercury can be harmful to humans and the environment if it is spilled during the removal of these devices.

The word “prevalent” in paragraph 1 is closest in meaning to_______.

A. rare

B. unusual

C. widespread

D. valuable

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 44.

Charles Lindbergh was born in Detroit, Michigan, in 1902 but was raised on a farm in Minnesota, where his father was elected to the U.S. Congress in 1907. From then on, he spent his boyhood alternately in Washington, D.C, and Little Falls, Minnesota. Because Lindbergh exhibited exceptional mechanical talent, in 1921 he was admitted to the university of Wisconsin to study engineering. However the young man was seeking more challenging endeavors, and two years later he became a stunt pilot who performed feats at county fairs and public assemblies. This unusual and dangerous undertaking paid off handsomely in the sense that it allowed him to gain a diverse and well- rounded experience in aeronautics. He particularly delighted in what he called "wing-walking" and parachute jumping.

After a year of training as a military cadet, Lindbergh completed his program at the Brooks and Kelly airfields at the top of his class and earned the rank of captain. Roberton Aircraft Corporation of St. Louis, Missouri, offered him employment as a mail pilot to run the routes between St. Louis and Chicago, and Lindbergh retained his position with the company until 1927. During this period, he set out to win the Raymond B. Orteig prize of $ 25,000 to be awarded to the first pilot to fly nonstop from New York to Paris. This ambition would irreversibly change his life and accord him a prominent place in the history of aviation.

Embarking on the greatest adventure of his time, Lindbergh left Roosevelt Field at 7:52 A.M on May, 20, 1927, and landed at Bourget Field at 5:24 P.M the next day. Fearing that he would be unknown when he arrived, Lindbergh carried letters of introduction to dignitaries in Paris, but when his plane came to a stop, he was overwhelmed by tremendous welcoming crowds. He was decorated in France, Great Britain, and Belgium, and President Coolidge sent a specially designated cruiser, the Memphis, to bring him back. His accomplishments in aeronautics brought him more medals and awards than had ever been received by any other person in private life. 

The word “undertaking” refers to

A. studying at the university.                     

B. exhibiting mechanical talent.

C. seeking challenging endeavors               

D. performing feats