Please excuse me _______ your letter by mistake.
All schools in our province ______ new English textbooks to improve students' listening,speaking,reading and writing abilities three years ago.
______ that the way people spend their holidays has changed a great deal in the past ten years.
He didn’t make ______ clear when and where the meeting would be held.
—You didn’t go to the party last night, did you? —I do wish I _________ there, but I had to do my homework.
You can’t legally take _______ of the property until three weeks after the contract is signed.