How should you warm up a diesel engine that has not been run for some time? （） ["Run it at minimum speed for a period of time","Run it at half speed for a period of time","Bring it to top speed immediately","Inject ether into the air intake"]
Concerning the management of sewage treatment plant using activated sludge, which of the following is correct?（） ["the plant should be prohibited to supplying air","the plant should work at intervals","the plant should be added disinfector in time","we should check strength of activated sludge, ivory-white color is best"]
在进行时间优化时，缩短关键路线上活动时间的途径有（）。 ["A.利用平行、交叉作业缩短关键活动的时间","B.在非关键路线上赶工","C.在关键路线上赶工","D.采用新技术缩短工作时间","E.进一步压缩最短路线上的工作时间"]
下面两幅图都采用了怎样的地图表现方法？
500kV线路并联电抗器操作规定有哪些？
为什么整流电路要滤波？
