[音频]3. A) Thefts of snowmobile dogs in Alaska.B) A series of injuries to snowmobile drivers.C) Attacks on some Iditarod Race competitors.D) A serious accident in the Alaska sports event.4. A) He stayed behind to look after his injured dogs.B) He has won the Alaska Iditarod Race four times.C) He received a minor injury in the Iditarod Race.D) He has quit the competition in Alaska for good.