He opened a book and began an invocation, which was certainly not English, and had a deep guttural sound.

他翻开一本书，开始召唤。咒语当然不是英语，倒是有很深的喉音。

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All of this is important in making your English sound more natural and conversational rather than something learned from a book.

所有这些都是重要的帮助，让你的英语听起来更自然、更像日常对话，而不是从书本里学到的东西。

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