17  

2. the rarest

3. important

4. clearly

5. smarter

6. the most valuable

7. harder

8. earler

18  

2) closer A

3) strongest A

4) more dangerous B

5) more popular A

6) the highest B

7) most serious B

8) the tallest A

19

2. a

3. a

4. b

5. c

6. a

7. a

8. c

9. c

10. b