the first I knew/heardused when you have just discovered something that other people already know, and you are slightly annoyed 我第一次知道/听说〔指刚知道其他人已知之事，并略感气恼〕 The first I knew he was in York was when I got an email from him. 我收到他的电子邮件才知道他在约克。
the first I knew/heard of/about The first I knew about it was when Tony called me. 托尼打电话来我才知道这件事。
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