上消化道出血,只表现有黑粪,估计每天出血量在()
A.20ml
B.50ml
C.50~100ml
D.250~300ml
E.400ml
参考答案:C
As physics is hard enough, I _____ study it.
A.amnotable
B.couldn’t
C.amnotableto
D.cannot
发现炭疽后,必须在8h内立即采取措施.进行隔离消毒。( )