自愿optional;voluntary;of one’s own accord;of one’s own free will
出于～on a voluntary basis;of one’s own free will/根據(jù)～的原則on a voluntary basis/自覺～ voluntarily;willingly;of one’s own free will/～互利的原則principle of voluntary participation and mutual benefit/～捐獻(xiàn)volunteer a donation/～遣返voluntary repratriation/～提供服務(wù)volunteer one’s services /～退出opt out /～獻(xiàn)血者volunteer donors of blood /～組織起來voluntary self-organization/～做某事volunteer to do sth /～者volunteer |