短语词组短语fall fall back on 求助于Fall off On 打开衰减fall down on rainfall 雨淋降落fall bak on 依靠fall back on experiments 求助于实验fall back on upon 求助于Fall colors on campus 校园的秋色fall down on stage 跌倒在舞台上fall back on 求助于;借助于;依赖;依靠 返回 fall on