几个词组的意思……
look back on/to think back to go back to date back to date from
look back on/to vt. 回顾(追想) think back to vt. 回想(回忆,重新思虑) go back to vt. 追溯到(回到...上来) date back to \ date from vt. 回溯到(开始于,从...的时候存在)
答:二者都可表示收到某人的信 ,但所接宾语不同 hear from sb receive a letter from sb详情>>