The mouse pointer displays a small empty square when resting on a point. Drag that point to another location. The curve on both sides of the point follows the movement; the section of the curve between the next points changes shape.
当鼠标指针停在接点上时，指针旁将显示一个空白的小方块。将接点拖到另一个位置。接点两侧的曲线也会随之移动，从而使相邻接点之间的曲线形状发生变化。