厚煤层分层开采,当顶板压力大时,为防止冒顶尽量选用()布置。
参考答案:内错式
哪项符合急性重症型病毒性肝炎的病理变化特点()。
A.嗜酸性变、形成嗜酸性小体
B.桥接坏死
C.碎片状坏死
D.广泛坏死
E.广泛性及点状坏死
Once you have established the daily ration of drinking water in a survival situation,how should you drink it?()
A.Small sips at regular intervals during the day
B.The complete daily ration at one time during the day
C.One-third the daily ration three times daily
D.Small sips only after sunset