它们可以展示在教室墙上。

They can be displayed on the classroom wall.

孩子们在教室墙上贴海报。

The children put up posters on the classroom walls.

测量是通过安装在教室墙上的隐蔽传感器装置实现的，并通过因特网把数据传送到远端的数据收集点。

Measurements were made using unobtrusive sensor packages mounted on classroom walls that transmitted data to a remote site using the Internet.