We can have ________ bluer sky if we create _________less polluted world.
Let’s ____ for a walk, shall we?
There were only two paintings for sale and he bought ____.
—Is your father ___ home? —No,he’s working late ____ the office.
The lovely girl is from Class6. ____ name is Alice.
--- Thank you very much for showing me the way to the station. --- ______.