迎刃而解

"Once the principal contradiction is grasped, all problems will be readily solved."

"一旦抓住了主要矛盾,一切问题就迎刃而解。"

Most of our social problems would be solved if we could somehow get rid of the immoral, crooked, and feebleminded people.

如果除不道德的、欺诈的和意志薄弱的人，们的多数社会问题就会迎刃而解。