Mother ______ him not to smoke, but he wouldn’t listen.

. It isn’t so much whether he works hard; the question is whether he works _____.

Professor Li preferred _______ lectures to his students to _______ to meetings on scientific developments.

________ take the aeroplane all the way, they decided to fly to Vancouver and then take the train from west to east across Canada.

At night we can see         stars in the universe．