form barrier的用法和樣例：
例句
- The farmers couldn't hold back the rising flood waters even with the barrier.
農民們擋不住上漲的洪水，即使設置障礙物也沒用。 - What is crucial is the attempt by one State to isolate itself from a problem common to many by erecting a barrier against the movement of interstate trade.
關鍵問題是，這一單個的州試圖以設置障礙阻止州際貿易流通的方式，使自己在一個大家共同面臨的問題中置身事外。
