"You outlined the plan in those letters?"
"No. They merely told my managers which salesmen I wanted for Oklahoma and the costs of the various drills."
"But a careful person, knowing the content of all those letters, could have worked out what you intended to do?"
"Yes, but no one person knew the contents of all the letters. Miss Winthrop and I were the only two human beings who knew what was in them all.
各位老师,同样都是content,为什么第二句用复数形式。这里有什么不同的表达的意思吗?