A rapid means of long-distance transportation became a necessity for the United States as settlement(新拓居地) spread over farther westward. The early trains were impractical curiosities, and for a long time the railroad companies met with troublesome mechanical problems. The most serious ones were the construction of rails able to bear the toad, and the development of a safe, effective stopping system. Once these were solved, the railroad was established as the best means of land transportation. By 1860 there’ were thousands of. miles of railroads crossing the eastern mountain ranges and reaching westward to the Mississippi. There were also regional southern and western lines. The high point in railroad building came with the construction of the first transcontinental sys tem. In 1862 congress authorized two western railroad companies to build lines from Nebraska west ward and from California eastward to a meeting point, so as to complete a transcontinental crossing link
A. 9 years
B. 7 years
C. 4 years
D. 3 years
A rapid means of long-distance transportation became a necessity for the United States as settlement(新拓居地) spread over farther westward. The early trains were impractical curiosities, and for a long time the railroad companies met with troublesome mechanical problems. The most serious ones were the construction of rails able to bear the toad, and the development of a safe, effective stopping system. Once these were solved, the railroad was established as the best means of land transportation. By 1860 there’ were thousands of. miles of railroads crossing the eastern mountain ranges and reaching westward to the Mississippi. There were also regional southern and western lines. The high point in railroad building came with the construction of the first transcontinental sys tem. In 1862 congress authorized two western railroad companies to build lines from Nebraska west ward and from California eastward to a meeting point, so as to complete a transcontinental crossing link
A. poor quality rails and unreliable stopping systems
B. lack of financial support for development
C. limited railroad lines
D. lack of a transcontinental railroad
Passage Two
A rapid means of long-distance transportation became a necessity for the United States as settlement (新拓居地) spread ever farther westward. The early trains were impractical curiosities, and for a long time the railroad companies met with troublesome mechanical problems. The most serious ones were the construction of rails able to bear the load, and the development of a safe, effective stopping system. Once these were solved, the railroad was established as the best means of land transportation. By 1860 there were thousands of miles of railroads crossing the eastern mountain ranges and reaching westward to the Mississippi. There were also regional southern and western lines.
The high point in railroad building came with the construction of the first transcontinental system. In 1862 Congress authorized two western railroad companies to build lines from Nebraska westward and from California eastward to a meeting point, so as to complete a transconti
A. Settlements Spread Westward
B. The Coast-to-Coast Railroad: A Vital Link
C. American Railroad History
D. The Importance of Trains in the American Economy
Do people who chose to go on deserve free health advice before they travel And even if they pay, who ensures that they get good, up-to-date information Who, for that matter, should collect that information in the first place For a variety of reasons, travel medicine in Britain is a responsibility nobody wants. As a result, many travelers go abroad ill prepared to avoid serious disease.
Why is travel medicine so unsolved Partly there’s an identity problem. Because it takes an interest in anything that 侵犯） on the health of travelers, this emerging medical specialism invariably cuts across the traditional disciplines. It delves into everything from seasickness, jet lag and the hazards of camels to 瘴气）and plague（瘟疫）.But travel medicine has a more serious obstacle to overcome. Travel clinics are meant to tell people how to avoid ending up dead of in a tropical disease hospital when
A. is for the government to decide.
B. should be left to specialist hospitals.
C. can be left to travel companies.
D. has no clear and simple answer.
有以下程序
#include
main(int argc,char *argv[])
{int i=1,n=0；
while(i
}
该程序生成的可执行文件为：proc.exe。若运行时输入命令行：
proc 123 45 67
则程序的输出结果是（）。
In sixteenth-century Italy and eighteenth-century France, waning prosperity and increasing social unrest led the ruling families to try to preserve their superiority by withdrawing from the lower and middle classes behind barriers of etiquette. In a prosperous community, on the other hand, polite society soon absorbs the newly rich, and in England there has never been any shortage of books on etiquette for teaching them the manners appropriate to their new way of life.
Every code of etiquette has contained three elements: basic moral duties; practical rules which promote efficiency; and artificial, optional graces such as formal compliments to, say, women on their beauty or superiors on their generosity and importance.
In the first category are consideration for the weak and respect for age. Among the ancient Egyptians the young always stood in the presence of
A. Respect for age.
B. Formal compliments.
C. Proper introductions at social functions.
D. Eating with a fork rather than fingers.
God and My Father
I thought of God as a strangely emotional being. He was powerful; he was forgiving yet obdurate, full of warmth and affection. Both his wrath and affection were fitful, they came and they went, and I couldn't count on either to continue: although they both always did．In short God was much such a being as my father himself.
What was the relation between them, I wondered — these two puzzling deities
My father's ideas of religion seemed straightforward and simple. He had noticed when he was a boy that there were buildings called churches; he had accepted them as a natural part of the surroundings in which he had been born. He would never have invented such things himself. Nevertheless they were here. As he grew up he regarded them as unquestioningly as he did banks. They were substantial old structures, they were resp
A. had been born in natural surroundings with banks and churches.
B. never really thought of God as having a real existence.
C. regarded religion as acceptable as long as it did not interfere.
D. regarded religion as a way that he could live a spiritual life.
Conflict And Competition
The question of whether war is inevitable is one which has concerned many of the world’s great writers. Before considering the question, it will be useful to introduce some related concepts. Conflict, defined as opposition among social entities directed against one another, is distinguished from competition, defined as opposition among social entities independently striving for something which is in inadequate supply. Competitors may not be aware of one another, while the parties to a conflict are. Conflict and competition are both categories of opposition, which has been defined as a process by which social entities function in the disservice of one another. Opposition is thus contrasted with cooperation, the process by which social entities function in the service of one another. These definitions are necessary because it is important to emphasize that competition between individuals or groups is
A. War.
B. Conflict.
C. Competition.
D. Cooperation.
阅读下面文字，回答题后问题：
基于潮流和波浪而产生的周期性流动以外的、比较固定的水流叫洋流。海水会经历几十年甚至数百年的时间在全世界的海域中循环，洋流指的是这种地球规模的海水循环的一部分。在洋流中，有像陆地上的河流一样幅度较窄而流速快的，也有幅度无限宽广而流速缓慢的，其大小、强度不能一概而论。以代表性的洋流之一——黑潮为例，在强流带时可达到2．5米／秒的速度，水流的路径、速度随季节和年代的不同都会发生很大变化。一般意义上的洋流，是在大海的表层流动(表层流)，而深层的水流则较弱，速度在每秒几厘米以下，水流的结构也很复杂。
表层洋流的发生，首先是因为风。水面上一起风，由于风力作用，水层就被拖动。表层的水一动，因海水彼此之间存在摩擦力，下面的水层便接连不断地被拖动。实际上，洋流并非沿着风的方向前进。像洋流这种地球上的大规模运动通常要受到地球自转的影响，即要受到科里奥利力的作用。在北半球，运动物体所受科里奥利力在其运动方向垂直的右方起作用。这样，海水就偏离了风力作用的方向，在北半球、表层洋流沿偏离风向约四五度的右方流动。
海面并不是完全水平的，温度、盐分、海水密度等多种因素使得海面凹凸不平。笼统来说，水温高的部分密度小，水面就高。水流理应从高处向低处流，但是由于科里奥利力的作用，高处的水流沿偏右的方向流动，这称为地衡流。海水的盐分等因素也可造成海水密度不同。海水中溶人了各种各样的物质，其中钠和卤素占绝大多数。另外，也有镁、钾、钙等盐类。盐分浓度会随年蒸发量、降水量而发生变化。此外，有河流等大陆水流注入的沿岸海域盐分较少，这些都影响洋流的流向。
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