过去常常

      used to

      介词（主要是to）的用法_爱问知识人 ... listen to 收听, used to过去常常, give birth to 过生日, ...

      used to do

      高中英语新课程标准词汇表 ... used to sth. 习惯于 used to do sth. 过去常常 wait for 等候，等待 ...

      Often in the past

      大学英语翻译~很急很急~_百度知道 ... 吸收 to digest 过去常常Often in the past 航行 to sail ...