Answer:
Industrial weapons contributed to staggering casualties and the western front was forced to use trench warfare. In order to prevent a two-front war, General Alfred von Schlieffen drew up a master plan calling for an all-out attack against France.
In this example, john's whistling is serving as a discriminative stimulus.
This procedure, studied by Ivan Pavlov, shows a stimulus ( in this case the action of John's whistling) and a response ( the cattle run to the food trough).
Pavlov studied it with dogs. He realised that when a trainer fed them, dogs salivated. So, he presented the dogs with a "stimulus" ( the sound of a metronome) and when he gave the dogs food. After a few repetitions, when the dog listened to the stimulus, it salivated.
President Richard Nixon proposed the development of the Environmental Protection Agency
<em>Postal Service mail carriers deliver mail to homes and businesses in cities, towns, and rural areas. Most travel established routes, delivering and collecting mail. Carriers cover their routes by foot, vehicle, or a combination of both.</em>