一人一兀
充分條件(Sufficient condition );必要條件( prerequisite);充分必要條件(sufficient prerequisite);必要充分條件(necessary sufficient condition).
離風(fēng)攜妻同行
必要條件,充分必要條件,必要充分條件Necessary conditions, sufficient and necessary conditions, necessary and sufficient conditions
優(yōu)質(zhì)英語(yǔ)培訓(xùn)問(wèn)答知識(shí)庫(kù)