Similarly, we explain many usability concerns as "it's an external component" or "it's a bell and whistle."

同样的，我们解释了很多关于“它是一个外部组件”或者“它是一个钟表或者汽笛”的可用性。

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The external size, quality, brake, handle-bar bell and night reflectors of a non-motor vehicle shall be in conformity with the safety and technical standards for non-motor vehicles.

非机动车的外形尺寸、质量、制动器、车铃和夜间反光装置，应当符合非机动车安全技术标准。

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