医生 / 提醒 / 他 / 出门 / 时 / 戴帽子 / 以免 / 晒斑 / 越来越 / 明显

医生提醒他出门时戴帽子，以免晒斑越来越明显。

The doctor reminded him to wear a hat when going outside so that his sunspots would not become more noticeable.