簡單卻困擾我的英文問題.help me out，please

Question

問題一、water 和 air　皆為不可數名詞，請問若 "air and water" 當主詞時，be 動詞要用　is 還是 are 呢？ 　　　Air and water is... ? Air and water are...? 列出二則例句參考。 a．Clean air and water are essential to the good health of a population. b．Clean air and water is not just possible in Kern County. 間題二、　”you or...

Answer 1

當你把 "water and air"當作是一體或一件事時，用單數
例如

Clean air and water is not just possible in Kern County.

但你要區分他們，或是有數(ㄕㄨ3)數(ㄕㄨ4)的動作時，用複數。
例如

Clean air and water are two most essential things to life.


間題二、　”you or he”當主詞時，後面動詞要用is


間題三、　”tea or milk” 當主詞時，後面動詞要is

Answer 2

這關係到主詞動詞一致 clean air and water are... 是指乾淨的空氣和水 clean air and water is... 是指乾淨的空氣與乾淨的水 視作者想表達什麼而定
you or he, tea or milk 都以靠近動詞的主詞為依據 所以 you or he 用 is, tea or milk 用 is

Answer 3

a句的主詞是clean air與clean water兩個。意為乾淨的空氣和乾淨的水對人的健康都很重要。

b句的主詞是clean air and water這個整體，強調的重點是乾淨。

you or he後一定是is

tea or milk後也是is

Answer 4

間題二、　”you or he”當主詞時，後面動詞要用are 還是is?

you / we / they === are Eg. you are, we are, they are
I am
he / she / it === is

Answer 5

既然有 and ,指水跟空氣這兩樣東西,那就是複數啦!
當然用are

既然是or ,當然是用 is