--The research on the new bird flu virus vaccine is challenging and demanding. Who do you think can do the job?--________ my students have a try?
---Oh, doctor, the wound on my leg is infected. ---You really shouldn’t have left it _______ to the sun.
Not everybody attending the meeting agreed to the suggestion ______ by the chairman.
----- Dad, look! I can reach the vase on the shelf. ------__________ you’ll break it.
_____ in her best skirt, the girl tried to make herself ____ at the party.
I _______ my son not to walk beside the river, but he wouldn’t listen.