keep a file的用法和样例：
例句
- The police kept a file of missing vehicle.
警察留有丢失车辆的档案。 - He keeps a file of letters so he can get his hands on one whenever he needs it.
他把信件归档保存，一旦需要就可以立刻找到。
keep a file的相关资料：
临近单词
keep pet
keep
keep the critical points cool
keep guard over the prisoners
Keep that boy from yelling.
keep something in one's bosom
Keep a sketchbook or notebook
Keep it simple and focused.
Keep Hong Kong Clean Campaign
keep records by notching wood
Keep one's secrets to oneself
keep something within compass
