（ ）5. Which is _______, the moon or the earth?
A. big B. bigger C. biggest D. the biggest
（ ）6. He is one of ________ in the world.
A. the great person B. the greatest
C. the greatest persons D. the great persons
（ ）7. Mobile phones are very popular now and they are ________ than before.
A. cheap B. cheaper C. cheapest D. the chepest
（ ）8. I’m fourteen. My friend is sixteen. So I’m _____ him.
A.as old as B.not younger than C.not so young as D.two years younger than
