1.D

2.C

3.B

4.A

5.C

6.D

7. Positive unit length

8. The ones on the right

9. everywhere

10. 10

1 1.-2 or 8

12. Less than greater than

13.

14.( 1) Yes, 1. (2) Yes,-1. (3)0, 1,2

15.( 1)- 12 & lt； -9 & lt； -6 & lt； -2 & lt； 5< 16 (unit: ℃) (2) is 7℃ higher.

16.B

17.C

Pure hand tour, the accuracy is absolutely guaranteed, I hope the landlord will adopt it.