The scattered single barchan dunes on the non sand bed possess movability and form unstability except the high large crescent sand mountain.

非沙质床面零星分布的单个新月形沙丘具有明显的移动性和形态的不稳定性（高大新月形沙山除外）。

The benefits of movability in wireless communication and high capacity in optical communication are combined in optical wireless system technology.

光无线系统技术结合厂无线通信的可移动性和光通信的高容量的优点。