李老师在体检时,经医生测定他的血压为19/14kPa,表明李老师的( )
A.收缩压高
B.舒张压高
C.收缩压和舒张压都高
D.收缩压和舒张压正成
答案:C
Can you imagine that a smart man like him_____ make such a stupid mistake?
A.might
B.should
C.would
D.need
什么叫标准密度?