English Across the Curriculum
Airplanes take off and land on runways. Big passenger planes need long runways that are up to 4 or 5 km in length . They may look like ordinary paved roads but are made of a special material so that they won't crack when heavy planes land. Snow ploughs and machines that spread salt keep them snow- and ice-free in winter. Green, red and white lights mark runways so that pilots can see them at night and when visibility is bad. Airplanes use taxiways to move to the main runway or to hangars . Small trucks bring big planes out of the parking zone.