This is the mechanical type of communication, which includes the use of signal flags, the 21-gun salute, horns, and sirens.
这是一种机械式的传播，包含信号旗、21响礼炮、号角、汽笛。
3
They jump the gun and start adding stimulus control while they are still using signals to help the dog Then when they drop the signal they confuse the dog.