Answer: The correct answer is : They must have separate compressed air tanks to fill their air reservoirs
Explanation: Modern air rifles used for small game have a small tank of compressed air integrated in the gun. Large caliber air rifles are designed to hunt larger games. Depending on the weight of the projectile, you can usually make multiple shots before filling each air tank.
Douglas MacArthur,
In July 1941, MacArthur was recalled to active duty and became commander of U.S. forces in the Pacific. A Japanese invasion of the Philippines that same year drove MacArthur’s forces from the country, but in the years that followed, MacArthur launched a number of successful offensive operations against the Japanese military in the region. During this time, he was frequently and openly critical of his superiors’ decision to focus military resources on the war in Europe rather than in the Pacific.