問題詳情：
改錯：By the time he realizes he walked into a trap, it'll be too late for him to do anything about it.
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【回答】
walked前加has 句意：在他意識到自己已經走進圈套時，對他來說，已無能為力了。根據句意可知用現在完成時。
知識點：現在完成時及其被動式
題型：短文改錯
