发现早期直肠癌最有效的方法是()。
A.直肠指诊
B.大便隐血
C.直肠镜
D.CEA
E.钡灌肠
参考答案:C
What really ________ is not failure itself, but the attitude we have towards it.
A.matters
B.applies
C.stresses
D.functions
单核苷酸多态在人群中的频率().
A.>1%
B.>5%
C.<5%
D.<1%
E.>2%