Complex sentence: One weather strike, out of 83 flown, was lost on January 10, but help was on the way as new B-29s from the United States were arriving almost daily and new groups were arriving in the Marianas.
Split into simpler sentences: One weather strike, out of 83 flown, was lost on January 10. New B-29s from the United States were arriving almost daily and new groups were arriving in the Marianas.