Eye contact is sometimes the key to communication. It can signal friendliness or hostility, interest or boredom, and understanding or confusion.
有时候，眼神接触是交流的关键。它可以成为表达友好或敌意，感兴趣或者不耐烦，理解或者困惑的信号。
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Even so, there are a great many absorption lines of other sorts that can lead to confusion, with different lines potentially masking the signal depending on whether Mars is coming or going.