—Mary,who’s ____ man over there?—He is my uncle, ____ English teacher.
---What should we do to fight A/H1N1 flu? ---We should wash hands often, avoid ______ to crowded places and so on.
The doctor did what he could_________ the dying man.
---Where does John live? ---He lives on ______ floor but he doesn’t use a lift to go up and down.
—What bad weather! —Yes. If it _______raining, the fields will be covered with water soon.
-I wonder ____________. -Zebras.