USAGE NOTE 用法说明: each, every, all and 和 both
Use each with a singular countable noun to mean 'every person or thing in the group considered separately'. each 和单数可数名词连用，表示“团体中作为单独概念的每一个人或每一件物”:
Each child at the party was given a present. 晚会上每一个孩子都得到一份礼物。
Use every with a singular countable noun to mean 'every person or thing in a group, considered together'. every 和单数可数名词连用，表示“团体中作为整体概念的每一个人或每一件物”:
Every child in the class passed the test. 班里每个孩子测验都及格了。
Use all with a plural countable noun to mean 'every one of a group of things or people'. all 与复数可数名词连用，表示“一组物或人中的每一个”:
All the children enjoyed the trip. 这次旅行所有的孩子都玩得很开心。
Use both with a plural countable noun to mean 'two people or things, considered together', both 和复数可数名词连用，表示“一起的两个人或两件物”:
Both our children are in college. 我们的两个孩子都在上大学。