2.？ (1) 0,5, minus 2/7? (2) 1、-2.5(3)5

3./0/=0/ 1/= 1/2.5/=2.5/-3/=3

4.-3? -1+2.5+5 A:-1 and+1 are antonyms.

5.( 1) A: B is 1200 and C is 2400. ? (2) Answer: 1200 and-1200 are antonyms.

6.？ (1) A: 2, -2 is just two (2)- 1 and 3.

*7? A: This number is-1.

(*^__^*)? Hee hee ... Did Yao Yao do the right thing?