15000 bài tập tách từ đề thi thử môn Tiếng Anh có đáp án (Phần 48)

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 first each of the numbered blanks from 501 to 505.

Nowadays people are more aware that wildlife all over the world is in (501)________. Many species of animals are threatened, and could easily become (502)________. if we do not make an effort to protect them. In some cases, animals are hunted for their fur or for other valuable parts of their bodies. Some birds, such as parrots, are

caught (503)________. and sold as pets. For many animals and birds the problem is that their habitat - the place

where they live - is disappearing. More land is used for farms, for houses or industry, and there are fewer open spaces than there once were. Farmers use powerful chemicals to help them to grow better crops, but these chemicals pollute the environment and (504)________. wildlife. The most successful animals on earth - human beings - will soon be the only ones (505)________., unless we can solve this problem.

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

As heart disease continues to be the number-one killer in the United States, researchers have become increasingly interested in identifying the potential risk factors that trigger heart attacks. High-fat diets and "life in the fast lane" have long been known to contribute to the high incidence of heart failure. But according to new studies, the list of risk factors may be significantly longer and quite surprising.

Heart failure, for example, appears to have seasonal and temporal patterns. A higher percentage of heart attacks occur in cold weather, and more people experience heart failure on Monday than on any other day of the week. In addition, people are more susceptible to heart attacks in the first few hours after waking. Cardiologists first observed this morning phenomenon in the mid-1980, and have since discovered a number of possible causes. An early-morning rise in blood pressure, heart rate, and concentration of heart stimulating hormones, plus a reduction of blood flow to the heart, may all contribute to the higher incidence of heart attacks between the hours of 8:00 A.M. and 10:00 A.M.

In other studies, both birthdays and bachelorhood have been implicated as risk factors. Statistics reveal that heart attack rates increase significantly for both females and males in the few days immediately preceding and following their birthdays. And unmarried men are more at risk for heart attacks than their married counterparts. Though stress is thought to be linked in some way to all of the aforementioned risk factors, intense research continues in the hope of further comprehending why and how heart failure is triggered .

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

Until recently, hunting for treasure from shipwrecks was mostly fantasy; with recent technological advances, however, the search for sunken treasure has become more popular as a legitimate endeavor. This has caused a debate between those wanting to salvage the wrecks and those wanting to preserve them.

Treasure hunters are spurred on by the thought of finding caches of gold coins or other valuable objects on a sunken ship. One team of salvagers, for instance, searched the wreck of the RMS Republic, which sank outside the Boston harbor in 1900. The search party, using side-scan sonar, a device that projects sound waves across the ocean bottom and produces a profile of the sea floor, located the wreck in just two and a half days. Before the use of this new technology, such searches could take months or years. The team of divers searched the wreck for two months, finding silver tea services, crystal dinnerware, and thousands of bottles of wine, but they did not find the five and a half tons of American Gold Eagle coins they were searching for.

Preservationists focus on the historic value of a ship. They say that even if a shipwreck's treasure does not have a high monetary value, it can be an invaluable source of historic artifacts that are preserved in nearly mint condition. But once a salvage team has scoured a site, much of the archaeological value is lost. Maritime archaeologists who are preservationists worry that the success of salvagers will attract more treasure-hunting expeditions and thus threaten remaining undiscovered wrecks. Preservationists are lobbying their state lawmakers to legally restrict underwater searches and unregulated salvages. To counter their efforts, treasure hunters argue that without the lure of gold and million-dollar treasures, the wrecks and their historical artifacts would never be recovered at all.