【简答题】A.Flies need less sleep than humans. B.Humans need a similar amount of sleep with flies. C.The amount of human sleep is determined by certain gene. D.Flies can determine how much sleep they need.
【单选题】Dawn flies regularly between Atlanta and Los Angeles. She almost always uses Delta Airlines and has lots of Delta Sky Miles credit (Delta's frequent flyer program). Still, she uses an online fare comp...