regular cusp的用法和樣例：
例句
- A cusp is also called a stationary point or point of retrogression gression.
尖點也叫做平穩點或逆行點。 - The amount of track points, including the double cusp points, which could be mostly realized by this kind of synthetic problems, was analyzed.
分析了包括雙尖點在內，該類綜合問題最多能實現的軌跡點數目。
