Some scientists believe that there will be more robots inyears.

He looks very pale. He may have _______ fever.

Look! The students are playing on the playground. Some are running, some are playing basketball, ________ are watching.

What a nice bike! Is it new?—No. I have _________ it for 2 years.

Now the air in our city is ______ than it used to be. Something must be done to stop it.