潘潘大小J
在这里用 necessary形容词 和necessity 名词两个都可以，根据不同句型，分别是It is necessary for a driver to be familiar with cars.或者 It is a necessity for a driver to be familiar with cars.本人留美多年，句子保证正确，如果还有问题可以找我~
MayQueen小乖
回答和翻译如下：必要条件，充分必要条件，必要充分条件。Necessary conditions, sufficient and necessary conditions, necessary and sufficient conditions.
会思想の萝卜
充分条件(Sufficient condition );必要条件( prerequisite);充分必要条件(sufficient prerequisite);必要充分条件(necessary sufficient condition).
穿G2000的恶魔
必要条件，充分必要条件，必要充分条件Necessary conditions, sufficient and necessary conditions, necessary and sufficient conditions
