Morse dash

例句：

1. 1.The Morse dash code is used to transmit messages over long distances.
   莫尔斯电码被用来在长距离上传输信息。
2. 2. In Morse dash code, each letter of the alphabet is represented by a series of short and long dashes.
   在莫尔斯电码中，每个字母由一系列短和长的点划表示。
3. 3. The Morse dash code was developed by Samuel Morse in the early 19th century.
   莫尔斯电码是在19世纪初由塞缪尔·莫尔斯开发的。