相关单词近义词 diffidence 无自信, retardation 智力迟钝, subnormality 逊常态, slowness 缓慢, mental retardation 智力迟钝临近词backward, backward decay, backward power, backward going, backward curve, backward lunge, backward branc, backward class, backward chanel, backward search, backward caries 返回 backwardness