一次浮选流程适用于中等可浮或难浮煤。
参考答案:错
— Ann is in hospital.
— Oh, really? I ______ know. I ______ go and visit her.
A.didn't, am going to
B.don't, would
C.don't, will
D.didn't, will
下列哪一选项不是蜂窝夹层结构的优点?()
A、具有较大的弯曲刚度和弯曲强度
B、具有较好的吸声和隔热隔声的性能;具有较高的耐声振疲劳性能
C、具有光滑的气动外形,气密性较好
D、抗湿热环境的能力好