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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 following questions.
These stories of killer bees in the news in recent years have attracted a lot of attention as the bees have made their way from South America to North America. Killer bees are reputed to be extremely aggressive in nature, although experts say that their aggression may have been somewhat inflated. The killer bee is a hybrid- or combination- of the very mild European strain of honeybee and the considerably more aggressive African bee, which was created when the African strain was imported into Brazil in 1955. The African bees were brought into Brazil because their aggression was considered an advantage: they were far more productive than their European counterparts in that they spent a higher percentage of their time working and continued working longer in inclement weather than did the European bees. These killer bees have been known to attack humans and animals, and some fatalities have occurred. Experts point out, however, that the mixed breed known as the killer bee is actually not at all as aggressive as the pure African bee. They also point out that the attacks have a chemical cause. A killer bee stings only when it has been disturbed; it is not aggressive by nature. However, after a disturbed bee stings and flies away; it leaves its stinger embedded in the victim. In the viscera attached to the embedded stinger is the chemical isoamyl acetate, which has an odor that attracts other bees. As other bees approach the victim of the original sting, the victim tends to panic, thus disturbing other bees and causing them to sting. The new stings create more of the chemical isoamylacetate which attracts more bees and increases the panic level of the victim. Killer bees tend to travel in large clusters or swarms and thus respond in large numbers to the production of isoamyl acetate.
The subject of the preceding paragraph was most likely
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word for each of the blanks
Are you a fan of the popular logical puzzle that (1) _____ by the name Sudoku? Even if you’re not, the chances are you know somebody who is. Once (2) _______ known outside Japan, this addictive brain teaser has become a common feature of newspaper puzzle pages all over the world.Sudoku’s great success (3) ______ much to its simplicity. The game (4) _______ for neither mathematical ability nor (5) ________ knowledge and there are just a few sentences of straightforward instructions to read before you can play. The only skill required is the ability to recognize the difference between nine different symbols, and these don’t even have to be numbers.Some clever marketing has helped the game. Western newspapers worked hard at promoting the game. Without this, it is unlikely that it would have (6) ______ off and become quite such a runaway success. The same also (7) ______ from its Japanese name that made people in many parts of the world (8) ______. It as a superior kind of puzzle compared to those you usually find in newspapers and magazines. But the popularity of Sudoku reached a peak in 2006, if the number of (9) ______ on one leading website is anything to go by. Newspapers responded by (10) ______ up with new kinds of logical puzzles, all with simple rules and Japanese names. But for true Sudoku fans, only the real thing will do.
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.
Pollution is a threat to many species on Earth, but sometimes it can cause species to thrive. Such is the case with Pfiesteria piscicida. A one-celled creature called a dinoflagellate, Pfiesteria inhabits warm coastal areas and river mouths, especially along the eastern United States. Although scientists have found evidence of Pfiesteria in 3,000-year-old sea floor sediments and dinoflagellates are thought to be one of the oldest life forms on earth, few people took notice of Pfiesteria.Lately, however, blooms – or huge, dense populations – of Pfiesteria are appearing in coastal waters, and in such large concentrations the dinoflagellates become ruthless killers. The blooms emit powerful toxins that weaken and entrap fish that swim into the area. The toxins eventually cause the fish to develop large bleeding sores through which the tiny creatures attack, feasting on blood and flesh. Often the damage is astounding. During a 1991 fish kill, which was blamed on Pfiesteria on North Carolina’s Neuse River, nearly one billion fish died and bulldozers had to be brought in to clear the remains from the river. Of course, such events can have a devastating effect on commercially important fish, but that is just one way that Pfiesteria causes problems. The toxins it emits affect human skin in much the same way as they affect fish skin. Additionally, fisherman and others who have spent time near Pfiesteria blooms report that the toxins seem to get into the air, where once inhaled they affect the nervous system, causing severe headaches, blurred vision, nausea, breathing difficulty, short-term memory loss and even cognitive impairment.
For a while, it seemed that deadly Pfiesteria blooms were a threat only to North Carolina waters, but the problem seems to be spreading. More and more, conditions along the east coast seem to be favorable for Pfiesteria. Researchers suspect that pollutants such as animal waste from livestock operations, fertilizers washed from farmlands and waste water from mining operations have probably all combined to promote the growth of Pfiesteria in coastal waters.
What is true of Pfiesteria?