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问题 判断题

失灵保护的动作时间应大于故障元件断路器跳闸时间和继电保护返回时间之和。

答案

参考答案：对

解析：

题目来源：电力系统继电保护实用技术问答（第五章）

专业类型：继电保护

设备类型：母线

难度等级：一般

电压等级：220kV

知识点：基础知识

问答题

Where one stage of child development has been left out, or not sufficiently experienced, the child may have to go back and capture the experience of it. A good home makes this possible, for example by providing the opportunity for the child to play with a clockwork car or toy railway train up to any age if he still needs to do so. (46)This principle, in fact, underlies all psychological treatment of children in difficulties with their development, and is the basis of work in child clinics.
The beginnings of discipline are in the nursery. Even the youngest baby is taught by gradual stages to wait for food, to sleep and wake at regular intervals and so on. If the child feels the world around him is a warm and friendly one, he slowly accepts its rhythm and accustoms himself to conforming to its demands. (47)Learning to wait for things, particularly for food, is a very important element in upbringing, and is achieved successfully only if too great demands are not made before the child can understand them.
Every parent watches eagerly the child’s acquisition of each new skill — the first spoken words, the first independent steps, or the beginning of reading and writing. (48)It is often tempting to hurry the child beyond his natural learning rate, but this can set up dangerous feeling of failure and states of anxiety in the child. This might happen at any stage. A baby might be forced to use a toilet too early; a young child might be encouraged to learn to read before he knows the meaning of the words he reads. (49)On the other hand, though, if a child is left alone too much, or without any learning opportunities, he loses his natural zest for life and his desire to find out new things for himself.
Learning together is a fruit source of relationship between children and parents. By playing together, parents learn more about their children and children learn more from their parents. Toys and games which both parents and children can share are an important means of achieving this co-operation. Building-block toys, jigsaw puzzles and crossword are good examples.
Parents vary greatly in their degree of strictness or indulgence towards their children. Some may be especially strict in money matters; others are severe over times of coming home at night, punctuality for meals or personal cleanliness. (50)In general, the controls imposed represent the needs of the parents and the values of the community as much as the child’s own happiness and well-being.
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单项选择题

下列描述不正确的是（）

A.寿命表是根据特定人群的年龄组死亡率编制出来的一种统计表

B.反映该人群平均存活的年限

C.寿命表中各项指标不受人口年龄构成的影响

D.不同人群的寿命表指标具有可比性

E.寿命表中主要的指标有“死亡概率”、“死亡人数”、“尚存人数”及“预期寿命”
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