retreat基本解释
n,撤退；休息寓所；撤退
He saw her and retreated, too shy to speak to her..他看到她就躲开了，不好意思跟她讲话。
退避，后退；撤退vv
re(向后) ＋ treat(=tract， 拉拽) → 向后拉 → 撤退， 退却记忆
retreat into oneself退隐；离群索居
