填空题

July 26, 2002
Dear Wang Wei,
I am terribly sorry to tell you that I have lost the valuable book Who Moved My Cheese You were so kind to lend it to me last week. I read it every evening and finished it last night. I intended to return it today, but when I came to my bedroom, it was no where to be found. I tried to find it everywhere, but I failed to, so I will get a new copy for you.
But I am afraid it can never take the place of the old one. Old books are like old friends. Once lost, they can never be replaced. And for this irrecoverable (无法弥补的) loss, I am to blame. I was so careless with my things, This is a warning to me to be more careful in future.
Please accept my sincere apologies.
Yours,
Wei Hua
What shortcoming must the author overcome in the future
The ______ with his things.

【参考答案】

carelessness