普通混凝土干表现密度为()㎏/m3。
A.2000~2800
B.2100~2850
C.2200~2900
D.2200~2950
参考答案:A
据《素问·太阴阳明论》,脾病不能为胃行其津液,则病()
A.泄泻
B.四肢不用
C.水肿
D.饥不受食
E.腹痛
-_______ did your uncle leave his hometown?
-He _______ for nearly twenty years.[ ]
A. When; has left
B. When; has been away
C. How long; has left
D. How long; has been away