高压油断路器中绝缘油有什么作用？
参考答案：
绝缘油在少油式断路器中主要用来熄灭电弧，在多油式断路器除用于熄灭电弧外，还起绝缘作用。
油断路器在切断负荷电流或故障电流时，其动、静触头之间要产生电弧，电弧的高温使油迅速分解并产生大量气体，在来弧装置的作用下，这些气体对电弧产生纵吹和横吹，使弧柱迅速冷却，增强了弧隙的去游离作用，这样随着断路器触头距离拉长，弧隙的绝缘强度恢复，使电弧熄灭。
油断路器的油面标准，应按规定保持在上、下红线之间。
阅读下面的短文，掌握其大意，然后从各题所给的四个选项中选出一个最佳答案。 Many children act in TV shows. They work several hours every day, _____ they can't go to regular _____. How do they get their schooling? In Hollywood, about forty ______ give lessons for the children. Their work is very ______. They make sure that the child ______ many different subjects. They make sure, ______, that the child gets enough _____ and play. Children in Hollywood must attend classes twenty _______ each week. If not, they can't _______ in TV shows any longer. TV children are usually ______ pupils, and most of their teachers ______ this kind of work. They give the pupils ______ in many interesting _______. Sometimes the “classroom” is a Mississippi _____. Sometimes it is the inside of a spaceship. Often the pupils become ______ stars.
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