A.近视眼只能看清近处的物体,看不清远处的物体
B.近视眼晶状体太厚,折光能力太弱
C.近视镜片是凸透镜
D.近视是来自远处的光线会聚在视网膜后
答案:A
A normal distribution can be completely described by its:()
A. mean and variance.
B. skewness and kurtosis.
C. mean and mode.
以下哪项是纵隔神经源性肿瘤的CT特征()
A.凸向肺野的肿块,有坏死区
B.肿块深入椎间孔内
C.肿块与肺界线清楚
D.肿块中等强化
E.肿块强化明显