按照专业性质，设备管理部门可分为四个组，分别为强电组、暖通组、（）和维修组
参考答案：弱电及电梯组
Henry killed the dog. I'll ask him why ________.
A．did he do that
B．he did that
C．he did
D．he has done so
毒物按其致毒作用可划分为剌激性﹑麻醉性﹑窒息性及（）毒物等。
A、心脏病
B、肝炎
C、胃病
D、致癌性
