单选题According to the passage, if the low lands were completely deforested the altitude of the cloud base would ______.

单选题The history of English is conventionally, if perhaps too neatly, divided into three periods usually called Old (or Anglo-Saxon)English, Middle English, and Modern English. The earliest period begins with the migration of certain Germanic tribes from the continent to Britain in the fifth century A. D, though no records of their language survive from before the seventh century, and it continues until the end of the seventh century or a hit later. By that time, Latin, Old Norse(the language of the Viking invaders), and especially the Anglo-Nor-man French of the dominant class after the Norman Conquest in 1066 had begun to have a substantial impact on the vocabulary, and the well-developed inflectional (词尾变化的) system that typifies the grammar of Old English had begun to break down. The period of Middle English extends roughly from the twelfth century through the fifteenth. The influence of French(and Latin, often by way of French)upon the vocabulary continued throughout the period, the loss of some inflections and the reduction of others accelerated, and many changes took place within the grammatical systems of the language. A bypical prose passage, specially one from the later part of the period, will not have such a foreign look to us as the prose of Old English, but it will not be mistaken for contemporary writing either. The period of Modern English extends from the sixteenth century to our own day. The early part of this period saw the completion of a revolution in vowel distribution that had begun in late Middle English and that effectively brought the language to something resembling its present pattern. Other important early developments include the stabilizing effect on spelling of the printing press and the beginning of the direct influence of Latin, and to a lesser extent, Greek on the vocabulary. Later, as English came into contact with other cultures around the world and distinctive dialects of English developed in the many areas which Britain had colonized, numerous other languages made small but interesting contributions to our word-stock.

单选题The use of helium for deep-sea diving

单选题Why will the call for a change in the use of the funds be opposed?

单选题Glass is everywhere in our lives. It is so common 1 we hardly think about it. We 2 it when we look out of the window and if we wear glasses. We drink from it and sometimes eat from it. The light in our homes comes through glass windows in the daytime and from glass lights 3 . Glass 4 in homes, schools, businesses, industry, and automobiles. Fortunately for us, glass is 5 very inexpensive materials. The main material is sand from quartz rock. The mixture is heated until it becomes a syrupy 6 . When the liquid cools, it becomes glass. No one knows 7 first discovered glass or how. Early humans used obsidian, a natural glass 8 by volcanoes, to make tools and jewelry. People probably began making glass themselves around 3000 B.C. in Syria. Then in a war 9 Egypt and Syria in 1400 B. C., Syria became part of Egypt. The Egyptians took Syrian glassmakers 10 to Egypt, and over the centuries the entire eastern Mediterranean area became a glassmaking center. Probably around 300 B.C. the blowpipe 11 . Egyptian glassmakers developed the use of the blowpipe. They specialized 12 beautiful jewelry, dishes, and other containers. The Romans soon started making their own glass. Then they 13 that glass could be used to make windows. 14 centuries later, Europeans made magnificent church windows 15 colored glass. 16 1900 companies have developed many new types of glass. Safety glass is a sandwich of glass and plastic. If it breaks, the pieces stay together 17 flying in all directions. This invention is very useful 18 automobile windows. Today most glass is made 19 machines in large factories. No one 20 it. People use television and computers to control the machines.

单选题What is the main feature of the grammar of Old English?

单选题Questions 11～13 are based on the following dialogue about a precious photo. You now have 15 seconds to read Questions 11～13.

单选题Questions 17～20 are based on the following dialogue about giving advice about trip. You now have 20 seconds to read Questions 17～20.

单选题[此试题无题干]

单选题With the extension of democratic rights in the first half of the nineteenth century and the ensuing decline of the Federalist establishment, a new conception of education began to emerge. Education was no longer a confirmation of a pre-existing status, but an instrument in the acquisition of higher status. For a new generation of upwardly mobile students, the goal of education was not to prepare them to live comfortably in the world into which they had been born, but to teach them new virtues and skills that would propel them into a different and better world. Education became training; and the student was no longer the gentleman-in-waiting,but the journeyman apprentice for upward mobility. In the nineteenth century a college education began to be seen as a way to get ahead in the world. The founding of the land-grant colleges opened the doors of higher education to poor but aspiring boys from non-Anglo-Saxon, working-class and lower-middle-class backgrounds. The myth of the poor boy who worked his way through college to success drew millions of poor boys to the new campuses. And with this shift, education became more vocational: its object was the acquisition of practical skills and useful information. For the gentleman-in-waiting, virtue consisted above all in grace and style, in doing well what was appropriate to his position; education was merely a way of acquiring polish. And vice was manifested in gracelessness, awkwardness, in behaving inappropriately, discourteously, or ostentatiously. For the apprentice, however, virtue was evidenced in success through hard work. The requisite qualities of character were not grace or style, but drive, determination, and a sharp eye for opportunity. While casual liberality and even prodigality characterized the gentleman, frugality, thrift, and self-control came to distinguish the new apprentice. And while the gentleman did not aspire to a higher station because his station was already high, the apprentice was continually becoming, striving, struggling upward. Failure for the apprentice meant standing still, not rising.