下列选项中哪一项不属于M2M应用范畴?()
A、机器对机器
B、人对机器
C、机器对人
D、人对人
参考答案:D
— It took me ten years to build up my business, and it almost killed me.
— Well, you know what they say. _____. [ ]
A. There is no smoke without fire
B. Practice makes perfect
C. All roads lead to Rome
D. No pains, no gains
不锈钢管道在油清洗前宜先进行处理的工艺为( )。
A.脱脂 B.酸洗C.用蒸汽吹净 D.钝化