电器工作时，发热和散热不同时存在于电器发热过程中。
参考答案：错
A fire has broken out on the stern of your vessel. You should maneuver your vessel so the wind（）.
A.blows the fire back toward the vessel
B.comes over the bow
C.comes over the stern
D.comes over either beam
250-350km/h线路轨道质量指数（TQI）管理值为（）
A.3
B.4
C.5
D.6
