15000 bài tập tách từ đề thi thử môn Tiếng Anh có đáp án (Phần 4)

(1) Increasing numbers of parents in the U.S. are choosing to teach their children at home. In fact, the U.S. Department of Education has estimated that in 1999, about 850,000 children were being homeschooled. Some educational experts say that the real number is double this estimate, and the ranks of homeschooled children seem to be growing at the average rate of about eleven percent every year.

    (2) At one time, there was a theory accounting for homeschooling: it was traditionally used for students who could not attend school because of behavioral or learning difficulties. Today, however, more parents are taking on the responsibility of educating their own children at home due to their dissatisfaction with the educational system. Many parents are unhappy about class size, as well as problems inside the classroom. Teacher shortages and lack of funding mean that, in many schools, one teacher is responsible for thirty or forty students. The children are, therefore, deprived of the attention they need. Escalating classroom violence has also motivated some parents to remove their children from school.

    (3) Although there have been a lot of arguments for and against it, homeschooling in the U.S. has become a multi-million dollar industry, and it is growing bigger and bigger. There are now plenty of websites, support groups, and conventions that help parents protect their rights and enable them to learn more about educating their children. Though once it was the only choice for troubled children, homeschooling today is an accepted alternative to an educational system that many believe is failing.

LEVELS OF VOCABULARY

Most languages have several levels of vocabulary that may be used by the same speakers. In English, at least three have been identified and described.

Standard usage includes those words and expressions understood, used, and accepted by a majority of the speakers of a language in any situation regardless of the level of formality. As such, these words and expressions are well defined and listed in standard dictionaries. Colloquialisms, on the other hand, are familiar words and idioms that are understood by almost all speakers of a language and used in informal speech or writing, but not considered acceptable for more formal situations. Almost all idiomatic expressions are colloquial language. Slang, refers to words and expressions understood by a large number of speakers but not accepted as appropriate formal usage by the majority. Colloquial expressions and even slang may be found in standard dictionaries but will be so identified. Both colloquial usage and slang are more common in speech than writing.

Colloquial speech often passes into standard speech. Some slang also passes into standard speech, but other slang expressions enjoy momentary popularity followed by obscurity. In some cases, the majority never accepts certain slang phrases but nevertheless retains them in their collective memories. Every generation seems to require its own set of words to describe familiar objects and events.

It has been pointed out by a number of linguists that three cultural conditions are necessary for the creation of a large body of slang expressions. First, the introduction and acceptance of new objects and situations in the society; second, a diverse population with a large number of subgroups; third, association among the subgroups and the majority population.

Finally, it is worth noting that the terms “standard”, “colloquial”, and “slang” exist only as abstract labels for scholars who study language. Only a tiny number of the speakers of any language will be aware that they are using colloquial or slang expressions. Most speakers of English will, during appropriate situations, select and use three types of expressions.

In addition to the great ridges and volcanic chains, the oceans conceal another form of undersea mountains: the strange guyot, or flat-topped seamount. No marine geologist even suspected the existence of these isolated mountains until they were discovered by geologist Harry H. Hess in 1946.

He was serving at the time as naval officer on a ship equipped with a fathometer. Hess named these truncated peaks for the nineteenth-century Swiss-born geologist Arnold Guyot, who had served on the faculty of Princeton University for thirty years. Since then, hundreds of guyots have been discovered in every ocean but the Arctic. Like offshore canyons, guyots present a challenge to oceanographic theory. They are believed to be extinct volcanoes. Their flat tops indicate that they once stood above or just below the surface, where the action of waves leveled off their peaks. Yet today, by definition, their summits are at least 600 feet below the surface, and some are as deep as 8,200 feet. Most lie between 3,200 feet and 6,500 feet. Their tops are not really flat but slope upward to a low pinnacle at the center. Dredging from the tops of guyots has recovered basalt and coral rubble, and that would be expected from the eroded tops of what were once islands. Some of this material is over 80 million years old. Geologists think the drowning of the guyots involved two processes: The great weight of the volcanic mountains depressed the sea floor beneath them, and the level of the sea rose a number of times, especially when the last Ice Age ended, some 8,000 to 11,000 years ago.