Sprocket
['sprɒkɪt] or ['sprɑkɪt]
解釋/意思:
(noun.) thin wheel with teeth that engage with a chain.
(noun.) roller that has teeth on the rims to pull film or paper through.
埃尔维斯手打--From WordNet
解釋/意思:
n. a projection on the periphery of a wheel or capstan for engaging the chain.
手打:玛丽安