֮ġ˲ɳӵͼϵĳһ㴫˾оһص. е˾ܵӰ, ǲڸееоᱻƶ.

Ҫٻɳ,  [˲ɳ] ͼʾϰ. ɳ밴λ, һҪ͵ĲӸ, ڶڲҪ͵ĵص㰴. , Ҫµ򶼱<link="topic:line of sight"></link>֮. ɳԽֵĲӴ͵ĳ֮, ߿ٴһЩԶԿϮ..
