—Have you found out anything, sir?

—We are sure that the thief entered the house through the window instead of breaking in. You               have closed the window before you left.

       A．shouldn’t  B．must  C．couldn’t    D．might

―Have you found out anything, sir?

―We are sure that the thief entered the house through the window instead of breaking in. You ______ have closed the window before you left.

     A. shouldn’t           B. must           C. couldn’t                   D. might