tip : 指向一边倾斜或向上翻转、失去平衡或完全翻转过来。
- Don't tip your chair back like that, you'll fall.
slope : 指向上或向下渐渐倾斜的表面，多用于山、屋顶等缓缓倾斜。
- The football pitch sloped at the south end, so one half of the game had to be played uphill.
tilt : 指有意识地或长时间地使物体处于倾斜状态。
- He tilted his chair backwards and put his feet up on his desk.