You can think of one picture holding this word together: a small train that is hauled up a high slope, let go, and then thrown down, up and around a narrow track. Nobody is steering it, the drops come without warning, and the whole thing is over quickly. Everything this word does grows out of that ride.
這個字可以想成一個畫面：一列小車被拉上高坡，然後放手，一路被甩下去、甩上來、甩過急彎。沒有人在開它，落差說來就來，而且很快就結束。無論講的是遊樂園的設施，還是一段日子，都可以從這個「被載著忽上忽下」的畫面看出來。
登入就可以看每一支怎麼連回核心畫面。