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>> 成人高等教育 / 当代语法学研究
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佳题速递：
下列属于例外的问题有。 A、 组织结构变化 B、 重大投资 C、 重要人事任免 D、 重大政策制定管理学原理 合成词的构成类型有（） 当代语法学研究 19、The wheel was one of man's first invention and yet it has also proved one of the most useful. So wide and varied are the uses of wheels, in machines and vehicles of all kinds, that it is difficult to imagine what the world would be like without them. It is surprising to hear it said, therefore, that the wheel's importance will perhaps be greatly reduced by the end of the century by an invention so new as to be still unnamed.
The invention is a machine that floats above any surface on a cushion (垫子) of air. The cushion is formed when air is blown into the bottom of the machine. This part is shaped like a saucer turned upside down. If air is blown into this saucer, the machine rises to a height that may vary from a few inches to a few feet.
Industry is already using one form of the invention to deal with heavy loads. It can lift them with ease and since there are no wheels, and therefore no friction, they can be put into motion with the touch of a finger.
The new invention, however, is having a great effect on transport. Not only does it make expensive road systems unnecessary, but it enables vehicles to travel equally well over land or water. This unique ability to reach most destinations has given rise to the prediction that wheeled vehicles may be as uncommon at the end of the century as airplanes were at the beginning.统考英语阅读理解 物距do为()时，薄凸透镜（焦距为f）成缩小实像A、>2fB、2f＞do＞fC、D、=2f光纤通信 PIN的工作机制是A、光学非线性B、光电导效应C、外光电效应D、光生伏特效应光纤通信 在全总个体域下，用一阶逻辑将命题“火车都比轮船快”符号化为 离散数学（上）