【单选题】Besides proper diet, exercise is one of the key ___________of a healthy lifestyle.
【判断题】船舶发生火灾,若火势较大,为避免烟雾或毒气危及人员生命,直接扑灭时应打开所有通风
【判断题】[ ] One key to effective conflict-resolution is to deal with personalities rather than issues.
【单选题】It took me _____to find out the key to the drawer. [ ]
【简答题】(选做题)求图 示电路中的电流 I 和电压 U 。请写出详细的计算过程。
【单选题】Besides proper diet, exercise is one of the key ___________of a healthy lifestyle.
【判断题】任何一个矩阵都可以和单位矩阵相加( )A. √ B. ×