 Complete the following phrase:  Because National Guard units had been mobilized for over a year in December 1941, they were among the first to enter combat in the following months. Californias 251st Coast Artillery Regiment and Hawaiis 298th Infantry Regiment took part in the defense of Oahu on 7 December 1941, during the Japanese attack on Pearl Harbor. New Mexicos 200th Coast Artillery Regiment and two tank battalions made up of National Guard units from several states were part of the 