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2. ClozeA. abundantB. complicatedC. conflictD. confrontedE. distributedF. environmentG. highlightH. innovationI. intensifiedJ. outcomeK. rateL. reliableM. replaceN. sourceO. subsequentWater is life. We depend on it to keep us and the 1 healthy. Nonetheless, many people take water as a natural resource for granted. Today, the situation has changed. As the population of the world increases, and with it the demand for water, there is growing concern that our water supplies will not be as 2 as we think. Eighty countries now have water shortages and 2 billion people lack access to clean water. One billion people lack enough water to supply meet their basic needs.While nearly 70 percent of the world is covered by water, only 2.5 percent of it is fresh. This tiny amount of fresh water available on the planet has remained fairly constant over time and is 3 unevenly around the world. The growth of the world population, therefore, 4 competition for a clean supply of water every year. Worse still, humans are not efficient users. According to the United Nations, water use has grown at more than twice the 5 of population increase in the last century. The reality is that an increasing number of regions are 6 with water scarcity. By 2025, two-thirds of the world’s population may face water shortage.An adequate and 7 water supply is essential to the future of every country. To increase and conserve supplies of fresh water, many countries have been working at technological 8 , one of which is in the process of desalination. New filtration systems have been developed to 9 traditional heating methods. Thus the expected 10 can be achieved: lower costs.

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最早的钢筋混凝土结构设计理论,是采用以(_ )为基础的容许应力计算法,这种方法要求在规定的标准荷载作用下,按弹性理论计算得到的构件截面任一点的应力应不大于规定的容许应力.

A. 弹性理论
B. 塑性理论
C. 弹塑性理论
D. 以上都不对

如果桥梁结构的设计基准期定义为T=100年,但到了100年时( )。

A. 一定该桥梁就不能使用了
B. 不一定该桥梁就不能使用了
C. 该桥还能再用100年
D. 以上说法都不对

结构的( )的定义是指结构在规定的时间内,在规定的条件下,完成预定功能的概率。

A. 可靠度
B. 强度
C. 挠度
D. 安全度

当整个结构或结构的一部分超过某一特定状态而不能满足设计规定的某一功能要求时,则此特定状态称为该功能的( )。

A. 极限状态
B. 可靠状态
C. 临界状态
D. 失效状态

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