 
 <prompt> Wetin dem use take prevent seams for di runways? Based on di last question, write one context wey contain di answer. E fit be 1 - 20 sentences. Context: <response>: Airport construction blow well well during di 1960s wit di increase for jet aircraft traffic. Runways dem extend reach 3,000 m (9,800 ft). Di fields dem dey construct out of reinforced concrete using a slip-form machine wey dey produce continual slab with no disruptions along di length. Di early 1960s also see di introduction of jet bridge systems to modern airport terminals, an innovation wey eliminate outdoor passenger boarding. These systems dey common for United States by di 1970s. 