13. I didn't know where I put my luggage.
我不知道我把行李放在什么地方了。
还能这样说：
I forgot the right place of my luggage.
I had mislaid my luggage.
14. Please describe the lost belongings.
请描述下丢失的物品。
还能这样说：
Please give a description of the lost belongings.
Please tell me something about the lost belongings.
15. Your luggage has been found in a corner.
你的行李在一个角落里找到了。
还能这样说：
We have found your luggage in a corner.
We have located your luggage in a corner.
应用解析：
be done in a corner 秘密做地；
from the corners/all corners of the earth 从世界各处；
in a tight corner 陷于困境；
drive a person into a corner 将人逼入困境
16. An old man picked up my baggage by mistake.
一位老人错拿了我的行李。
还能这样说：
An old man mistook my baggage for his.
An old man took my baggage by mistake.
应用解析：
pick at sth. 小口地吃（某物）；
have a bone to pick with sb. 就某事跟某人辩论，争吵；
pick up on 对……熟悉起来；
pick sb.'s brains 问某人问题以获取有用的信息
17. The police have caught the man who stole your bag.
警察已经抓到了偷你包的人。
还能这样说：
The police have found the thief who stole your bag.
The man who stole your bag has been caught by the police.
应用解析：
catch sb. off one's guard 乘人不备，乘人不注意；
catch sb.'s death 造成某人之死；
catch sb. red-handed 当场抓住某人