活塞式液氧泵常见故障有哪些，如何处理？
参考答案：
高压液氧泵的常见故障有：
1）出口压力低。泵的转向错误、泵的转速不够、泵内有蒸气、进口过滤器堵塞等原因都可能造成泵的出口压力降低。处理方法是：停泵查看转向，如转向错误就调换电机接线；如转速不够需通知电工检查处理；如是泵内有蒸气就应停泵，打开排气管路，重新预冷；如是过滤器堵塞，就需拆开检查处理。
2）马达过载。叶轮组装不好、马达轴承润滑不好、输入电流过大等原因可能造成马达过载。需拆泵检查叶轮间隙、并作调整；填加润滑脂；请电工检查输入电流并加处理。
3）轴承温度低。冷却时间过长或密封泄漏可能造成轴承温度低。处理方法是：检查密封气的流量及压力。
任务型阅读(每空1分，共10分)（注意大小写，每空不只一词） Without proper planning, tourism can cause problems. For example , too many tourists can crowed public places that are also enjoyed by the inhabitants of a country. If tourists create too much traffic , the inhabitants become annoyed and unhappy. They begin to dislike tourists and to treat them impolitely .They forget how much the tourism help the country's economy. It is important to think about the people of a destination country and how tourism affects them. Tourism should help a country keep the customs and beauty that attracts tourists. Tourism should also advance the well-being of local inhabitants. Too much tourism can be a problem. I f tourism grows too quickly. people must leave other jobs to work in the tourism industry. This means that other parts of the country's economy can suffer. On the other hand , if there is not enough tourism , people can lose jobs. Business can also lose money. It costs a great deal of money to build large hotels, airports, first-class roads, and other support facilities needed by tourist attractions. For example , a major international class tourism hotel can cost as much as 50 thousand dollars per room to build .If the room is not used most of the time , the owners of the hotel will lose money. Title:1._____________
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