curve

The high-speed train tilted slightly as it rounded the sharp curve in the mountain tracks.

(Chinese) 高铁在绕过山间轨道的急弯时稍微倾斜了一下。

The graph shows a steep learning curve for students who are new to advanced calculus.

(Chinese) 图表显示，对于初次接触高等微积分的学生来说，学习曲线非常陡峭。