下列哪一条是错误的。() ["支撑应经常检查,发现支撑构件有弯曲、松动、移位或劈裂等迹象时,应及时处理;雨期及春季解冻时期应加强检查","拆除支撑前.应对沟槽两侧的建筑物、构筑物和槽壁进行安全检查,并应制定拆除支撑的作业要求和安全措施","施工人员应由安全梯上下沟槽,不得攀登支撑","采用钢板桩支撑时,构件的规格尺寸经计算确定,入土深度应根据经验确定"]
集权和分权是一个相对的概念。
关于交流电动机调速方法正确的是() ["变频调速","改变磁通调速","改变转子电压","定子串电阻调速"]
Given: What is the result?() ["Compilation fails.","atom granite","granite granite","atom granite granite","An exception is thrown at runtime.","atom granite atom granite"]
带式输送机不具有以下哪种特点?() ["运量大","能适应较小倾角","连续作业","运距长"]
网络成瘾的类型有哪些?