I’ve ______ the house since I moved here. [ ]
A. lived
B. bought
C. sold
D. had
答案:D
布置简单,基建投资少,运行管理方便,是热网最普遍采用的形式,此种管网布置形式为()。
A.平行管网
B.辐射管网
C.枝状管网
D.环状管网
一个圆的直径是15.6米,它的半径是多少?