抓斗天车必须持证上岗，启动前必须打铃，确认安全后方可启动_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题判断题

抓斗天车必须持证上岗，启动前必须打铃，确认安全后方可启动

答案

参考答案：对

选择题

Is this your necklace, Mary? I____ it when I was cleaning the bathroom this morning.

A．came across

B．dealt with

C．looked after

D．went for

判断题

视觉识别系统属于动态系统。