为什么英语说："an apple a day keep a doctor away."有什么科学根据呢?一天一个苹果为什么能远离病痛?

英语难题 Newton was playing under an apple tree ______ an apple fell onto his head.A.when B.while请选一个并说为什么 一道英语小题目,A saying says,( )a day keeps doctor away.A.A banana B.An orange C.An egg D.An apple.应该选哪个,为什么 为什么英语中要用“could you please give me a apple 而不用 an apple 为什么英语说：an apple a day keep a doctor away.有什么科学根据呢?一天一个苹果为什么能远离病痛? 请问为什么苹果和鸡蛋要用,an apple、an egg 而不是a apple、a egg an.Apple.a. an apple a day a red apple或者an red apple red apple 前面的冠词用a 还是an 为什么? a man eats an apple eat为什么要加s 为什么现在英语里表量词的“a”可以发音为/ei/许多外国人都这么说 请问这样子可不可以通过发 /ei/音来避免用an来修饰名词 即 this is a(/ei/) apple 一个红色的苹果 是a red apple 还是 an red apple 并且说出为什么 I'd like an apple对an apple提问 An Apple a Day 歌词 take ---apple and ---orange---to Bob,pleseA.a,the B.an,a C.an,an D.the,an Look,there're 后为什么填apple trees而不是apples trees或者是an apple tree 请回答时详细说下语法 还有个就是After ten yeas,all these youngsters became后有4个选择题A.growns-ups B.growns-up C.grown-up D.grown-ups 我不明 ()will keep you healthy.A:Have an apple each day B:Having an apple each day C:Having had an apple each day D:By having an apple each day 英语单选题：An apple ______ into the water.A.fell B.was fallen C.falls D.is fallenAn apple ______ into the water.A.fell B.was fallen C.falls D.is fallen