Today, air travel is far safer than driving a car on a busy motor way.However, there is a danger that grows every year.(1)_______________________.Air traffic controllers tell the pilot exactly when to turn, when to climb and when to come down.The air traffic controllers around a busy airport may handle 1 000 planes a day.Any plane that flies near the airport comes under the orders of the controllers there.Even a small mistake on their part could cause a disaster.Recently, such a disaster almost happened.Two large jets were flying towards the airport.One was carrying 69 passengers from Chicago.(2)_______________________.He ordered one to turn to the right and to climb,but he made a mistake:he ordered the wrong So, instead of turning away from the second plane,the first plane flew towards it.Fifteen seconds later,it flew directly in front of the second plane.They avoided each other by the smallest of a second.The distance between them was less than that of a large swimming pool.(3)___________________________