综采泵站压力的要求为()
A、≥25MPa
B、≥28MPa
C、≥30MPa
参考答案:C
your pets inside as much as you can when the weather is bad.
A.Keep
B.Keeping
C.Kept
D.To keep
具有自重轻、耐火性好的优点且安装简易的型钢是( )。
A.热轧型钢 B.冷弯薄壁型钢 C.轻钢龙骨 D.压型钢板