请帮忙看下这个句子的主谓宾. 我怎么找不到谓语

singletonboy

center 动词

center on

集中于。。。。

以。。。。为中心

shengxuf

The debate over bilingual education 主

centers on 喂

the issue of 宾

whether the这个是宾语从句，忘了中文咋说的了。
United States should foster the idea of single common language, an idea,
some believe, that has in the past been crucial in binding diverse
constituencies together.