That gives an effective control range of 30km.

有效控制范围为30公里。

One of the main reasons for having a smart home is the ability to control a whole range of devices from afar.

拥有智能家居的主要原因之一是能够远程控制各种设备。

For more than a hundred years they had controlled the open range from the Smoky Hill River to the Red, from the headwaters of the Canadian to the fork of the Arkansas and Cimarron.

一百多年来，他们一直控制着从烟山河到红河，从加拿大河源头到阿肯色河和西马龙河的分岔口的开阔山脉。