constant maintenance造句

• The machinery requires constant maintenance
  这些机器需要经常保养维修。
• The machinery requires constant maintenance
  这些机器需要经常保养维修
• The machinery requires constant maintenance
  机器需要经常养护。
• Women are like boats : they require constant maintenance and attention , and they cost a lot of money
  女人像游艇：需要定期的维护和关注，而且花费很高。
• This computer system minimized personnel requirements , but such linked computer systems are prone to failure without constant maintenance and are not practical for military starships
  这种电脑系统已经把个人用途限制到最小化，但是在没有持续的维护的情况下，这种连接式电脑系统很容易实效并且不适合军事舰只。
• But because of dc motor ' s complicated structure , manufacture consuming time , constant maintenance and so on , people try to replace the dc motor speed regulation with ac motor speed regulation . by the development of power electronics , pwm technology , computer control and ac motor control , ac speed regulation system is replacing ac speed regulation system by its many faults such as solidity , safety and so on
  20世纪80年代以前，要求调速的设备多用直流电动机调速，但由于直流电动机结构复杂，制造费时以及需要经常性维护等缺点，使得人们一直努力寻找能替代直流电动机调速的交流电动机调速。随着电力电子技术、 pwm调制技术、计算机控制技术、交流电动机的控制技术的发展，交流调速系统由于其坚固耐用、运行可靠等众多优点，正在逐步取代以前直流调速系统，在传动领域占据主导地位。