turning curve的用法和樣例：
例句
- Like a vertex of a polyline, it expresses a point on the object, but it also expresses the shape of the curve at the point.
和折線上的定點類似，它也表示對象上的點，不過這裡表示的曲線上的點。 - Architect can choose any kind of grooves,curve diversification or various curving styles with his pleasure.
建築師可以任意選擇凹槽和折線變化或各種曲線造型。
