Is the CN Tower the ________ tower in the world?
A．tall B．taller C．tallest
Niagara Falls is in ________．
A．China B．CanadaC．America
Would you like________to Australia?
A．go B．to go C．going
He is ________TV now.
A．watch B．watches C．watching
It's one of________ parks in the world.
A．the greatest B．greatest C．the great