一代高炉寿命取决于()状况。
A、炉顶
B、炉身
C、炉腰
D、炉缸
参考答案:D
用适当的介词填空
1. She participated her friend his sufferings.
负压锅炉在排烟过剩空气系数不变的情况下,炉膛漏风与烟道漏风对锅炉效率的影响相同。