YSK: Why U.S. radio and TV station call letters start with either a "W" or a "K".
from /r/YouShouldKnow
YSK：为什么美国电台和电视台的呼号以 "W "或 "K "开头。
YSK：为什么美国电台和电视台的呼号以 "W "或 "K "开头。
YSK: Why U.S. radio and TV station call letters start with either a "W" or a "K".
from /r/YouShouldKnow