Picture a school built as a doorway rather than a destination. Children study there for a few years, and the , the exams and the advice all point at the same exit: getting into the next school, the better one, the one with a gate you have to pass a test to enter. Change what sits on the far side of that doorway and you change which country you are talking about.
One branch
為了進入下一所學校而設的私立學校
兩個意思其實是同一張圖，只是門的另一邊換了東西。美式的下一關是大學，英式的下一關是十三歲的入學考。
noun · B2
In the US, a school, usually a private one, that teaches students in the years before university and whose main job is to get them ready to enter a good college.
（美）升大學的預備學校