and的用法的主谓一致Bread and butter____the everyday food in the west.(is/are)这个句子选哪个答案

is

楼上说得很好, 这里做进一步分析.
这是个有点微妙的问题, 就是用 "and" 连接的主要到底是单数还是复数, 你的这句话又加了一个层面的问题就是 "bread and butter" 是一个固定词组. 咱们先说"and":
1. 复合主语用 "and"连接, 表示一个整体, 是单数:
The secretary and treasurer has filed the minutes. (The secretary and treasurer is one person)
2. 如果每部分都有each 和 every来限制, 是单数:
Each player and every team receives a prize.
3. 除了上述情况, 用"and"连接都是复数:
Rain and snow were falling at the same time.
There are one book and two magazines on the table.
The computer and the printer are compatible.
The boys and their father are going together.
Now,你的例句中的 "bread and butter" 是个特殊的词组, 已经形成固定词组, 多数情况是做为一个整体, 也就是说是单数:
Bread and butter is eaten everyday.
但是, 也可以说:
Bread and butter are eaten everyday. 这里重点放在"bread" 和 "butter"两种食物上.
你的这个例句还有一个clue, 就是宾语是food, 是个单数.
希望我的解释解除你的疑惑.

is
由and连接的并列结构作主语,可根据主语的意义决定谓语动词的单、复数形式.
例如：
Good and bad taste are inculcated by example.
Fish and chips are getting very expensive.
A truck and a car were in the ditch.
当and连接的并列名词词组带有each,every,或者many a 等限定词时,谓语动词通常用单数.
例如：
Each man and each woman there is asked to help.
Every flower and every bush is to be cut down.
Every change of season,every change of weather,indeed every hour of the day,produces some change in the magical hues and shapes of these mountains.
Many a boy was disappointed after seeing the film.

本句填is ,因为 Bread and butter面包和黄油 ，是欧美人常吃的一种食物，是在 面包 上涂 黄油，因此实际上就是 涂着黄油的面包 ，他们作为一个食物的整体，因此是单数，所以用is.希望你掌握这种分析问题的方法，并能够在以后的学习实践中运用自如。