Which one of the following is used by sailors for communication before the invention of the telephone or radio?
Which one of the following is used by sailors for communication before the invention of the telephone or radio?
ٹیلیفون یا ریڈیو کی ایجاد سے پہلے مندرجہ ذیل میں سے کون سا ملاح مواصلات کے لئے استعمال ہوتا ہے؟
Explanation
Light signals, such as semaphore flags or lantern flashes, were commonly used by sailors to communicate over distances.
These signals conveyed messages visually before the invention of modern communication tools.