1. Prolonged heat can, moreover, enhance production of smog and the dispersal of allergens. 持续的高温也提高了烟雾的产量和过敏原的散布。
2. People at particular risk for the flu should therefore avoid prolonged exposure to the Sun. 因此，那些特别易受流感影响的人应避免长时间曝露在太阳底下。
3. The official White House forecast shows a nation stuck in purgatory for a prolonged period, with high unemployment persisting for years. 白宫官方预测显示，在一个较长时间内国家还在炼狱之中挣扎，高失业率会持续多年。
英英解释
adj.
1. relatively long in duration; tediously protracted
2. drawn out or made longer spatially
3. (of illness) developing slowly or of long duration
