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单选题 In the past raincoats were made of water-repellent materials whose solid composition allowed no ventilation. For this reason, raincoats were uncomfortable in hot weather. A porous material now has been invented in which the openings are too small to let water molecules through but large enough to allow ventilation for the wearer. Raincoats of this material provide both protection and ______
学科：2022-2023-2 工程学科英语
时间：2023-06-12 14:56:06
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题目1单选题
Years ago, before the invention of railway, the telegraph, the telephone, planes, and other means of carrying messages, from one place to another, fire signals and drum signals were used for fast transmission of messages. It is said that African drummers could send rather detailed information as far as 2000 kilometers in a day by relaying the drum messages from ______A. any directionB. rulers to subjectsC. runner to runnerD. village to village
题目2单选题
A manikin made of plastic and metal has been placed in a mechanical seat and subjected to a simulated car collision. The manikin is wired electronically to report the results of the crash. This equipment has aided in the production of better protective devices to minimize the bad effects of accidents. You may some day owe your life to ______A. a signalB. an automobileC. an accidentD. a dummy
题目3单选题
A simple compass can be made by floating a magnetized needle on a splinter of wood in water. The needle will turn and come to rest in a north–south direction nearly on the line from the North to the South Pole. The earliest record of the use of this device for guiding navigators is from the Mediterranean area in the twelfth century, although the magnetic phenomenon had been known for more than a thousand years. The mariner's compass was developed rapidly, and Christopher Columbus was able to use a compass very similar to our ______A. celestial navigationB. modern compassC. modern navigationD. crude compass
题目4单选题
Acetylene, an invisible gas, produces a flame whose light penetrates fog and darkness remarkable well. This property, along with the capacity of the acetylene generator to operate without attention for long periods of time, makes the gas valuable for use in ______A. blowtorchesB. industrial heatingC. weldingD. lighthouses
题目5单选题
The first underground railway was built in London in 1863 and was powered by steam locomotives. Underground railways are now powered by electricity, and many cities in all parts of the world have some kind of underground transport. The most extensive systems are in London, Paris, Moscow, and New York City. Because of the speed and low fare on these system, many city workers ______A. drive themB. build themC. avoid themD. use them
题目6单选题
Zinc can be melted down to form a coating substance. This metallic element also has the valuable characteristic of resisting rust. These two qualities make zinc a good substance to use for ______A. medicinal purposesB. cleansing metalsC. protecting other metalsD. treating dead wood
题目7单选题
Calcination is a process of heating certain solid materials to temperature high enough to remove volatile substances, or substances that evaporate readily. For example, the calcination of limestone involves heating the stone to a point high enough to expel unwanted carbon dioxide and to leave commercially desirable lime. Calcination, therefore, is sometimes referred to as process of ______A. deteriorationB. oxidationC. purificationD. replacement
题目8单选题
Alchemists were people who tried to find ways to turn inexpensive metals into gold and thereby become rich. The alchemist did not know that some metals change into other metals all by themselves. Radium, for example, changes into lead — an inexpensive metal. Even if the alchemists had known about this change, they probably would not have been concerned, for they were interested in ______A. changing gold to another metalB. becoming wealthyC. maintaining secrecy about their discoveriesD. using those metals that others had changed to gold
题目9单选题
In Japan, the making of samurai swords is a highly developed art. The swords are fashioned entirely by hand. Since no one would use an imperfect swords, there are no "seconds" among samurai swords. Each new sword is carefully tested by its maker; and if it fails to meet the required standard, it is ______A. given awayB. immediately destroyedC. priced downD. used by the sword-maker
题目10单选题
Many deep-sea divers are lowered and raised by a crew on the surface and receive their oxygen supply through tubes to the surface. Skin-divers use an independent system called scuba, self-contained underwater breathing apparatus. Open-circuit scuba equipment allows bubbles of air to come to the surface. Navy skin-divers use a closed or semi-closed circuit apparatus. With this type of apparatus, the enemy cannot detect the diver's presence because ______A. no bubbles escape to the surfaceB. the diver is down too deepC. the apparatus blends with the seaD. there is not boat in sight
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