听力原文： Listening is one of the first things we learn to do, and one of the things we do most. The average person spends 9% of his daily communication time writing, 16% reading, 30% speaking and 45% listening. Students spend most of their school time listening, up to 60% according to some studies. Yet despite its importance, we usually take our ability to listen for granted. As we've already said, though, listening isn't easy. In the first place, we're surrounded by noise: the sound of traffic, the roar of jets overhead, even the start tick on the telephone line, which makes any listening job a challenge. In the second place, we often don't seem to remember even when we do listen, by the time a speaker has finished a ten minutes' speech, the average person has already forgotten half of what was said. Within 48 hours, another fifty percent has been forgotten. In other words, we quickly forget nearly all of what we hear. Unfortunately, the cost of poor listening is high. Poor listening may keep you from doing well on an exam, but it can cost all of us much more. One of the greatest tragedies in the history of sea travel occurred on the night of April 14th, 1912, when the crew of the TITANIC refused to listen to repeated warnings of iceberg. Even after the ship struck an iceberg and was obviously sinking, some of the passengers ignored the captain's orders to get into the lifeboats. (43)