相关单词近義詞 compulsory 強制的, essential 本質的, necessary 必要的, vital 至關重要的, forced 被迫的, forcible 強制的, indispensable 不可缺少的, mandatory 法定的, requisite 必要的, obligatory 強制性的, prerequisite 先決條件, needful 必需的, needed 需要的反義詞elective, 選擧的臨近詞require, required time, required flow, required area, required list, required NPSH, require nerve, required over, require study, Required Date, required book 返回 required