单选题Being a man has always been dangerous. There are about 105 males born for every 100 females, but this ratio drops to near balance at the age of maturity, and among 70-year-olds there are twice as many women as men. But the great universal of male mortality is being changed now, by babies survive almost as well as girls do. This means that, for the first time, there will be an excess of boys in those crucial years when they are searching for a mate. More important, another chance for natural selection has been removed. Fifty years ago, the chance of a baby(particularly a boy baby)surviving depended on its weight. A kilogram too light or too heavy meant almost certain death. Today it makes almost no difference. Since much of the variation is due to genes one more agent of evolution has gone. There is another way to commit evolutionary suicide: stay alive, but have fewer children. Few people are as fertile as in the past. Except in some religious communities, very few women has 15 children. Nowadays, the number of births, like the age of death, has become average. Most of us have roughly the same number of offspring. Again, differences between people and the opportunity for natural selection to take advantage of it have diminished India shows what is happening. The country offers wealth for a few in the great cities and poverty for the remaining tribal peoples. The grand mediocrity of today everyone being the same in survival and number of offspring means that natural selection has lost 80% of its power in upper-middle-class India compared to the tribes. For us, this means that evolution is over; the biological Utopia has arrived. Strangely, it has involved little physical change. No other species fills so many places in nature. But in the pass 100,000 years — even the pass 100 year our lives have been transformed but our bodies have not. We did not evolve, because machines and society did it for us. Darwin had a phrase to describe those ignorant of evolution: they "look at an organic being as average looks at a ship, as at something wholly beyond his comprehension." No doubt we will remember a 20th century way of life beyond comprehension for its ugliness. But however amazed our descendants may be at how far from Utopia we were, they will look just like us.

单选题The Great Wall is a great tourist ______ , drawing millions of visitors from all parts of the world every year.

单选题Under an unstable economic environment, employers in the construction industry place great value on ___________ in hiring and laying off workers as their volumes of work wax and wane.

单选题Analysts have had their go at humor, and I have read some of this interpretative literature, but without being greatly instructed. Humor can be dissected, as a frog can, but the thing dies in the process and the innards (内在部分) are discouraging to any but the pure scientific mind. In a newsreel theatre the other day I saw a picture of a man who had developed the soap bubble to a higher point than it had ever before reached. He had become the ace soap bubble blower of America, had perfected the business of blowing bubbles, refined it, doubled it, squared it, and had even worked himself up into a convenient lather. The effect was not pretty. Some of the bubbles were too big to be beautiful, and the blower was always jumping into them or out of them, or playing some sort of unattractive trick with them. It was, if anything, a rather repulsive sight. Humor is a little like that: it won't stand much blowing up, and it won't stand much poking. It has a certain fragility, an evasiveness, which one had best respect. Essentially, it is a complete mystery. A human frame convulsed with laughter, and the laughter becoming mysterious and uncontrollable, is as far out of balance as one shaken with the hiccoughs or in the throes of a sneezing fit. One of the things commonly said about humorist is that they are really very sad people- clowns with a breaking heart. There is some truth in it, but it is badly stated. It would be more accurate, I think, to say that there is a deep vein of melancholy running through everyone's life and that the humorist, perhaps more sensible of it than some others, compensates for it actively and positively. Humorists fatten on trouble. They have always made trouble pay. They struggle along with a good will and endure pain cheerfully, knowing how well it till serve them in the sweet by and by. You find them wrestling with foreign languages, fighting folding ironing boards and swollen drainpipes, suffering the terrible discomfort of tight boot (or as Josh illings wittily called them, "tire boots"). They pour out their sorrows profitably, in a form hat is not quite a fiction nor quite a fact either. Beneath the sparking surface of these dilemmas lows the strong tide of human woe. Practically everyone is a manic depressive of sorts, with his up moments and his down moments, and you certainly don't have to be a humorist to taste the sadness of situation and mood. But there is often a rather fine line between laughing and crying, and if a humorous piece of writing brings a person to the point where his emotional responses are untrustworthy and seem likely to break over into the opposite realm, it is because humor, like poetry, has an extra content. It plays close to the bit hot fire which is Truth, and sometimes the reader feels. the heat.

单选题The well-maintained facility in San Francisco______leagues in virtually every sport.(北京大学2007年试题)

单选题The president gave a ______ for the visiting heads of the countries.

单选题The spy gave General Washington a ______ report on enemy activities.

单选题These continual______in temperature make it impossible to decide what to wear.(中国矿业大学2008年试题)

单选题The title that best summaries the content of the passage is most probably ______.

单选题This matter should not be bushed up, but freely ______.

单选题 James's first novels used conventional narrative techniques: explicit characterization, action which related events in distinctly phased sequences, settings firmly outlined and specifically described. But this method gradually gave way to a subtler, more deliberate, more diffuse style of accumulation of minutely discriminated details whose total significance the reader can grasp only by constant attention and sensitive inference. His later novels play down scenes of abrupt and prominent action, and do not so much offer a succession of sharp shocks as slow piecemeal additions of perception. The curtain is not suddenly drawn back from shrouded things, but is slowly moved away. Such a technique is suited to James's essential subject, which is not human action itself but the states of mind which produce and are produced by human actions and interactions. James was less interested in what characters do, than in the moral and psychological antecedents, realizations, and consequences which attend their doings. This is why he more often speaks of "eases" than of actions. His stories, therefore, grow more and more lengthy while the actions they relate grow simpler and less visible; not because they are crammed with adventitious and secondary events, digressive relief, or supernumerary characters, as overstuffed novels of action are; but because he presents in such exhaustive detail every nuance of his situation. Commonly the interest of a novel is in the variety and excitement of visible actions building up to a climatic event which will settle the outward destinies of characters with story-book promise of permanence. A James novel, however, possesses its characteristic interest in carrying the reader through a rich analysis of the mental adjustments of characters to the realities of their personal situations as they are slowly revealed to them through exploration and chance discovery.

单选题 Asbestos exposure results in Mesothelioma, asbestosis and internal organ cancers, and ______ of these diseases is often decades after the initial exposure.

单选题If they think they are going to win over us by obstinately ______ and refusing to make the slightest concession, they are mistaken.

单选题On______,18%ofourdailycaloriescomefromsugar.

单选题According to the passage, sloppy writing ______.

单选题Hardy was stimulated by the sights, sounds and smells about him; he was enjoying his sensuous experience.

单选题There are always a lot of {{U}}straw polls{{/U}} before the general election of the President in the United States．

单选题I asked my mother if I could go out, and she ______. A) descended B) contented C) consented D) ascended