-What do you think of the traffic in our city?-lt's    than it used to be, but there's still a long way to go.

 —If there are _____ people driving, there will be ____ air pollution.— Yes , the air around us will be fresher and cleaner.

More and more people have a low-C life and the air is _________ than before.

－Look at our model of space station. Do you like it?－Yes, it is even          than ours.

Mr. Brown is one of ______ teachers in the school. All the students like him.