下列不属按工程管线敷设方式分类的是( )。
A.架空线
B.重力自流管线
C.地铺管线
D.地埋管线
参考答案:B
已知命题p:x2-8x-20≤0,q:1-a≤x≤1+a(a>0),若非p是非q的充分不必要条件,求a的取值范围.
Class 12, Grade 8: Activity Survey
Activity
Every Day
Twice a Week
Four Times a Week
Watch TV
60%
20%
Have Sports
10%
70%
Do homework
100%
0%