A: In 2000, China's GDP was 8,940.4 billion yuan.

2. Solution: Set X chickens to avoid 200-X chickens. Then 2X+4(200-X)=536, so X= 132.

Assumption holds: there are x chickens, and 200-X chickens are exempted. Then 2X+4(200-X)=525, and X= 137.5.

So the assumption doesn't hold. Explain that according to the actual situation, the legs of chickens and rabbits are paired.

3. solution: let the length be x and the width be X- 12. According to the meaning, X/X- 12=5/3, so X=30.

A: The length and width of a rectangle are 30 and 18 respectively.

4. Solution: Let the tree be X and the poem be 3X+5=5(X- 1), so X=5.

There are (20) crows and (5) trees in the Poetry Bureau.

5. Solution: Let mechanical pencil x yuan, from the meaning of the question, 25(X+2.5)=80, so X=0.7.

A: Every 0.7 yuan in mechanical pencil.

6. Solution: Suppose you read page X on the first day, then: (X+X-30+X+40)2/5=X+40, so X= 180.

A: This book has 550 pages.

7. solution: let the white skin block be x, then: X+3/5X=32, X=20.

A: 0/2 pieces of black leather/kloc-and 20 pieces of white leather.

8. Solution: Let the price of refrigerator be X yuan, which can be listed as X (1-0.13)-100 =1726.13, and the solution is X= 2099.