ǻ֮ɪٻǻܼĳ. һܵǻػ, ڵĲľһ, , ˾Ѹ뿪, ܵ˺. Ӻͽǻػƻ.

Ҫʯ, ĻϷ [ǻ] ͼʾϰ, ȻڵͼϣΪҽϰ. , ʹô˷ĵص<link="topic:line of sight"></link>֮.
