目录
1，roller \pulley \wheel 这三个单词都是轮子的意思，有什么区别
A roller is a machine that helps moves objects along a surface but is not attached to the object.
A wheel is attached to the object that it is trying to move.
A pulley is used to lift a heavy load without using as much force as would normally be needed.
2，roller pulley wheel这三个单词都是轮子的意思，有什么区别
★ roller：滚柱；滚轴；滚筒。圆柱形或管筒状（cylinder, tube-shaped）。
例：压路机（前面是一个巨大的滚筒）：a road roller
★ pulley：滑轮；滑轮组；滑车。指称滑轮组这种物理机械中的滑轮。
例：我们的旗帜被用一根绳子和两个滑轮升到了竿顶。
Our flag is raised to the top of a pole by a rope and two pulleys.
★ wheel：轮；车轮；机轮。圆盘状或圆环状（disk-like, circular）。
例：自行车的轮子：the wheel of a bicycle；方向盘：the steering wheel