cycling is a fantastic way to burn a few calories and save some money, there still exist risks．

A．Since

B．While

C．As

D．When

脑出血与蛛网膜下隙出血之鉴别下述哪点最重要（）

A.活动中发病

B.头痛、呕吐

C.脑脊液含血量多少

D.CT见脑实质内高密度灶

E.脑膜刺激征