v.落下；跌倒；减少；沦陷n.落下；瀑布；秋天；减少 变形： 过去式：fell过去分词：fallen现在分词：falling第三人称单数：falls 双语释义：v.(动词)vi. 降落,落下; 摔下,倒下 come down from a higher place, e.g. by losing balance or as a result of gravityvi. 跌倒 come down from a standing position to a lying positionvi. 降低,减退 co