物联网(TheInternetofthings)是通过______、红外感应器、全球定位系统、激光扫描器等信息传感设备，按约定的协议，把任何物品与通信网连接起来，进行信息交换和通信，以实现智能化识别、定位、跟踪、监控和管理的一种网络。

A．RFID
B．GPRS
C．IPv6
D．MPLS

单句改错

1. It is a lot more excited to travel by air than by  water.        

2. You can see falling leaves everywhere in autumn.        

3. On arriving home, she found her husband looked worried.        

4. Losing in thought,he didn't hear what his teacher said at all.