ĹŬ˹ķٻһѵһ. ЩﲻĿ, Ҳ뿪Ǳٻ, ˼ʹ, Ҳ׷֮. , ǻֵ֧ɱΪֹ. ߶ԴĹ̫ǿ, ǲṥ.

ˮٻ, ٻĻˮ. ǲṥ洬, ṥս.

Ҫٻ,  [֮] ͼʾϰ, Ȼ<link="topic:line of sight"></link>ڵκһط. ޷´, Ҫܹ˺, ˵ĵصٻǳ.
