进料容器的下部,有()个煤粉疏松元件,使用惰气对进料仓的煤粉进行疏松,以改进煤粉21的流动性和防止煤粉在进料仓内架桥。
A.6
B.8
C.10
D.12
参考答案:A
They're out _____ milk. They must go to buy it. [ ]
A. on
B. at
C. for
D. of
服务区域按形状可分为:()和()。