-Is Jack on duty today?-It ____ be him. It’s his turn tomorrow.
—Won't you go shopping with your mother?—No.________ she promises to buy me a new sweater.
The result is very important.It is supposed ______ a secret between you and me.
Knowledge and learning are important if we want to be successful, but they may also ________our thinking.
The harder you ________, the better progress you ________.
Professor Smith is now ________ the company, which was once________ Professor White.