【正确答案】
Dear Wang Lin,
I am terribly sorry to tell you that I have lost the valuable book you were so kind to lend me last week. I read it everyday and intended to finish it next month. Last night when I came to my room, it was nowhere to be found. I will try to recover it as soon as possible. If I fail to find it, I will get a new' book for you.
But I am afraid it can never take the place of the old one. Oid books are like old friends. Once lost, they can never be replaced, and for this irrecoverable loss, I am to blame. I was so careless with my things. This is a warning to me to be more careful in the future.
Yours sincerely,
Li Ming