We oversimplified. In fact, there is no such thing as the injector! An application may have multiple injectors!

我们其实有点简化过度了。实际上，没有那个(唯一的)注入器这回事，一个应用中可能有多个注入器。

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Insulin pens are injector devices designed to allow multiple self-injections for one person, according to the Center for Disease Control and Prevention's website.

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