The river is over _________ wide.

Studies show that the things that contribute most to a sense of happiness cannot be bought，______ a good family life，friendship and work satisfaction.

Michael and Jane are talking ______ the telephone.

Two lawyers have donated $50,000 to ________ our school’s campaign “Help the Needy”, which was started by our former headmaster three years ago.

Will you take up teaching as a career after graduation?—- Hard to say. I ________ go abroad for higher education instead, but it depends.