管内强迫对流换热

A. There’S been nothing but rain for quite some time．
B. He’S bored with the changing weather．
C. He thinks that it’11 rain for three more weeks．
D. He’S bored about the topic on weather．

A. 已出租的土地使用权
B. 持有并准备增值后转让的土地使用权
C. 已出租的建筑物
D. 自用房地产

A. 碳酸锂
B. 氢氧化铝
C. 硫酸镁
D. 苯妥英钠
E. 氟哌啶醇