Final answer:
Pneumatic starters are usually designed with an entrainment system that utilizes increased fluid speed to create low pressures, which then entrain one fluid into another.
Step-by-step explanation:
Pneumatic starters are usually designed with an entrainment system that utilizes increased fluid speed to create low pressures, which then entrain one fluid into another. This is achieved through the use of entrainment devices such as atomizers, aspirators, and Bunsen burners.