retention
/rɪˈtenʃn; rɪ`tɛnʃən/ n[U, sing]
(fml 文)1 possession or use of sth 具有; 具备; 享有; 享用
retention of one's rights, privileges, etc 权利、 特权等的享有
the full retention of one's (mental) faculties （心智）能力的健全.
2 ability to remember things 记忆力; 记性
her limited/extraordinary powers of retention 她那有限的[非凡的]记忆力
show an amazing retention of facts, details, childhood impressions, etc 显示出对事实、 细节、 儿时情景等的惊人记忆力.
3 action of holding sth in position or containing it 挡住; 拦阻; 保持; 保留; 容纳
the retention of flood waters, crowds 拦住洪水、 人群
suffer from retention of urine, ie failure to pass it out from the bladder 患闭尿症（不能排尿）.