若代数式a-b的值是1,那么代数式2a-(3+2b)的值等于______.
∵a-b=1,
∴原式=2a-3-2b
=2(a-b)-3
=2×1-3
=-1.
故答案为-1.
绿地的适用坡度是下列哪项()
A.0.2%~0.5%
B.0.5%~1.0%
C.0.3%~2.5%
D.0.5%~7.0%
引下线优先采用圆钢,圆钢直径不应小于()。
A.8mm
B.10mm
C.12mm
D.16mm