High-speed aircraft usually employ thin, low-drag, low-lift airfoils; slow aircraft that carry heavy loads use thicker airfoils with high drag and high lift.
高速飞机通常采用低阻力、低升力的流线型薄翼型，载重量大的低速飞机使用高阻力、高升力的厚翼型。
They were fastened with great bars, most of them too high to reach and all too heavy to lift.
门上牢牢地拴着许多大门闩，大多数都高不可及，重不可举。
In hilly areas, water pumping irrigation lift is high, and the irrigation water fee is high because of the high pumping cost, so the burdens on farmers are very heavy.
丘陵地区提水灌溉需要的扬程高，水费占灌溉成本的比重大，农民的负担很重。
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