Which of these statements is TRUE of system building?

单项选择题What lifts the concrete panels onto the building?

单项选择题The usual fixed length in the modular system is_______.

单项选择题According to the passage, the principle of system building is that_______.

单项选择题In the last two hundred years there have been great changes in the method of production of goods. This is now also true of the building industry; for mechanization has been introduced. System building can save both time and money. The principle of system building is that the building is made from a set of standard units. These are either made at the building-site or at a factory. Some designers, in fact, are standardizing the dimensions of rooms. They are made in multiples of a single fixed length, usually ten centimeters. This is called a modular (标准件的) system, and it means that manufactures can produce standardized fittings at a lower cost. The most important fact about system building is its speed. A ten-storey flat, for example, can be completed in four months. There are several new methods of system building. One is the panel method. In this case, the construction company sometimes erects a factory on the site. The walls and floors of the building, called panels, are cast in a horizontal or vertical position. Conduits for electrical wires and sleeves for pipes are cast in the panels when they are being made. The moulds for making these castings are situated all around the building. After the concrete panels are cast, they are allowed to set and harden for a week. Next they are lifted by a tower crane on to any section of the building. There the panels are cemented together at their joints and the floor covering is laid. After the panels have been cemented together, the crane lifts a case into the area. It contains all the fittings to be installed, such as wash-basins, radiators and pipes. Finishing tradesmen, such as plumbers, plasterers, painters and electricians, follow behind to complete the work. In some building developments, in some countries, whole flats with internal features like their bathrooms, bedrooms and connecting stairs, and weighing as much as twenty tons, are carried to the building-site ready-made. A giant overhead crane is used to lift them into position. In the future, this method may become more widespread. The main difference between panel method and the method discussed in the last paragraph is_______.

单项选择题A.They will be fined。B.They will be closed。C.They will get a warning。D.They will lose customers。

单项选择题Among all the animals, the ape is most like human beings. Both people and apes have the similar brain structure, the similar nerve system, and the similar kind of blood. There are four kinds of apes: the chimpanzee(黑猩猩), the orangutan(猩猩), the gorilla(大猩猩), and the gibbon(长臂猿). They live in the deep forests and warm tropical regions of Africa and of Southeast Asia, including Indonesia. All apes are covered with brown, reddish-brown, or black hair everywhere on their bodies except their faces, feet, and hands. Their hands each have four fingers and a thumb that helps them grip things the way our thumbs help us. But they also have a thumb on each foot instead of a big toe. Thus they can hold things with their feet also. Having short, weak legs, apes do not walk on the ground very much. However, their arms are very strong. This enables them to swing from branches and travel very quickly from tree to tree. These animals live in small family groups that move from place to place in search of vegetables and fruits. They also eat eggs, small animals, nuts, and insects. When they are tired, they build nests in the trees. But they rarely sleep there for more than a night or two. Then they move on to look for more food. There are some differences among the following three kids of apes. The gibbon is never more than three feet high and weight only about fourteen pounds. The gorilla grows to be six feet tall and weight up to 600 pounds. The orangutan is smaller than the gorilla. It stands three to five feet tall and weight up to 200 pounds. Chimpanzees are the smartest of all apes. They can be taught to sit at a table and eat, to dress themselves, and to do things that human children can do. What does the first paragraph tell us?

单项选择题According to the passage, why was Bemardino Cirillo disappointed with the music of his time?

单项选择题'This practice' in Paragraph 4 refers to_______.

单项选择题Agriculture is the number one industry in the United States and agricultural products are the country's leading export. American farmers manage to feed not only the total population of the United States, but also millions of other people throughout the rest of the world. Corn and soybean exports alone account for approximately 75 percent of the amount sold in world markets. This productivity, however, has its price. Intensive cultivation exposes the earth to the damaging forces of nature. Every year wind and water remove tons of rich soil from the nation's croplands. Each field is covered by a limited amount of topsoil, the upper layer of earth which is richest in the nutrients and minerals necessary for growing crops. Ever since the first farmers arrived in the Midwest almost 200 years ago，cultivation and, consequently, erosion have been decreasing the supply of topsoil. In the 1830s, nearly two feet of rich, black top soil covered the Midwest. Today the average depth is only eight inches, and every decade another inch is blown or washed away. This erosion is steadily decreasing the productivity of valuable cropland. A United States Agricultural Department survey states that if erosion continues at its present rate, corn and soybean yields in the Midwest may drop as much as 30 percent over the next 50 years. So far, farmers have been able to compensate for the loss of fertile topsoil by applying more chemical fertilizers to their fields; however, while this practice has increased crop yields, it has been devastating for ecology. Agriculture has become one of the biggest polluters of the nation's precious water supply. Rivers, lakes, and underground reserves of water are being filled in and poisoned by soil and chemicals carried by drainage from eroding fields. Furthermore, fertilizers only replenish the soils they do not prevent its loss. The last sentence in the first paragraph gives an example to show_______.

单项选择题The closest restatement of the last sentence in,the 3rd paragraph is______.