compulsory的反义词有哪些
compulsory的反义词有：elective, optional, voluntary, elective, spontaneous, voluntary, convex, optional, liberal。
adj.
compulsory的反义词（强迫的;选修的）：elective, optional, voluntary。
compulsory的反义词（其他释义）：elective, spontaneous, voluntary, convex, optional, liberal。