The river has become much ______ than before because of the waste water from the factories.
A. dirty B. dirtier C. dirtiest
In China, spring returns in March. The weather ______ warm and the days are longer.
A. gets B. sounds C. smells
A computer ______ think for itself. It’s always told to do things.
A. mustn’t B. can’t C. shouldn’t
Lily’s apartment is on the fifteenth ______ of the building and it has a good view.
A. room B. part C. floor
Where is your father?
He ______ Xiamen on business.
A. will go to B. goes to C. has gone to