门静脉系统扩张可由以下哪些病变所致()①右侧心力衰竭②肝硬化③二尖瓣狭窄
A.①②
B.②③
C.①③
D.①②③
参考答案:A
—______ will you repair the bike, Uncle Wang?
—In half an hour. [ ]
A. How long
B. How often
C. How soon
介质损耗因数数值的大小,对新油而言,反映的是();对运行油而言,反映的是()。