试管中有一段被水银柱密封的空气柱,将此试管分别如图所示旋转,若空气柱的压强为p,大气压为P,则满足P<P的是[ ]
A、甲
B、乙
C、丙
D、乙和丙
答案:A
—Joe, can you answer the phone for me, please? I supper.
—OK, Mum. [ ]
A. was cooking
B. cook
C. am cooking
D. cooked
内痔分期主要的依据是
A.全身症状
B.疼痛
C.便血
D.脱出
E.患病时间