I'm afraid there ______ much time left. Let's hurry.[ ]
A. isn't
B. aren't
C. is
答案:A
设a=π0.5,b=log32,c=cos2,则a,b,c从大到小的顺序为______.
肺出血可选用
A.垂体后叶素B.缩宫素C.加压素D.前列腺素E.麦角新碱