热水供应系统由哪几部分组成
参考答案:由热源、加热设备和管道系统组成。
It’s quite ______ me why such things have been allowed to happen.
A.for
B.behind
C.against
D.beyond
MCC的102项特服号码路由表指向第几个中继群。()
A.1
B.2
C.15
D.16