Lesson 7 背景知识听力填空Listen and fill in the blanks with proper words based on what you have heard.[音频]After the local controller has __1__ airplane through the take-off phase, the pilot will be instructed to change __2__ and contact the departure controller. Departure controllers work at the __3__ radar approach facility and they direct the airplane from the airport __4__ to the center’s airspace. The departure controllers __5__ the airplanes which are identified by their__6__on the radar screen. The tag provides controllers with much information such as flight number, aircraft type, airspeed and altitude. Controllers rely on this information to keep all __7__ aircraft at safe distance with each other. In order to maintain__8__ spacing among departing aircraft, departure controllers might also direct the pilot to turn the airplane to different __9__ heading or have the aircraft climb or descend or to have it fly faster or slower. When the departure controllers guide each aircraft through specific __10__ and when the aircrafthasreachedthe assigned __11__ altitude, they will perform electronic transfer of the flight to the center controller. When the center controller sees the electronic __12__ on the radar screen, the departure controllers will instruct the pilot once again to change radio frequency and contact the __13__ controller. Theywill monitor the flight until it reaches the __14__ of the radar screen.