黑箱测试将软件看作一个“黑箱”，测试工程师没有关于内部实现的知识，他们以将使用该产品的客户身份在软件上执行测试。
Black-box testing treats the software as a "black box," without any knowledge of internal implementation and the test engineer will perform tests on the software as a customer would use the product.
销售代表也会学习关于客户方面的知识，所以在出售一件产品或一项服务前，他们会花很多时间去聆听顾客的需要。
Sales representatives also educate themselves about their clients, so they spend a lot of time listening to the customer's needs and concerns before selling a product or service.
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