I. 1.c2.b3.b4.a

Second, five. Goldbach conjecture 6. Jiangsu "The reason why the solution of Sujiaju's algebraic quintic equation can't be established"

7.6 120 8.90 9. 12 18 8 2 10.8 12 6 2 1 1.4

12. Addition, commutative law 13.2 3 14. Even number 0 or 5 15.3 3 3.

16.0 1 0 and 1

Three. 17.( 1) 200200 (2) 3.8 (3) 3000 (4) 120

18.( 1) 185 (2)2500 (3)2550 (4)5050

19.( 1)696 (2)0 (3) 1 (4) 1232

Four. 20. The total length of stairs is (3+4) × (4–1) = 21(m).

∴: What's the speed of Xiao Wang going upstairs?

2 1.( 1)

(2)

(3)

22.( 1)[29.9 1–29.9 1÷( 1+6.7 1%)× 1000–[ 13.78÷( 1–6%)– 13.78]×500

= 1.89× 1000–0.88×500

= 1890–44

= 1846 (yuan).

(2) The total opening price is 29.91÷ (1+6.71%)+13.78 ÷ (1–6%) = 28.02+/kloc.

(3) The sum of the closing prices of the above two stocks is 29.91+13.78 = 43.69 yuan.

(4) As can be seen from the table, Liuyang Fireworks is the biggest winner and Stard is the biggest loser.

23. let the black skin have a block, and the white skin has a block.

Black leather 12 pieces, white leather 20 pieces.

24. Let this number be, then there is ("∫" means because, "∴" means like this).

If it weren't for this,

Then look down.

Yahoo! Com/question/140712020112.html is on this website.

It says

Lesson one

There is no answer at all. It comes with the book.

So it is unrealistic to buy.

I won't talk nonsense with you.

Register at /index.php (this is a website for practicing one lesson at a time) (just register casually), and then click it to see a web page. There is an "important notice" on the edge of the page, and you can see the e-book of one lesson and one practice answer in 2008, which is the answer.

It took me a long time to find it ... remember to give points when you find it ~

Hmm. How interesting