0 abbreviation for erectile dysfunction -- 勃起机能障碍，勃起无力（erectile dysfunction的缩写）
1 abbreviation for effective dose: the amount of a drug that produces the effect that is wanted -- 有效剂量（effective dose的缩写）
2 used to form the past simple and past participle of regular verbs -- （用于构成规则动词的过去式和过去分词）
