影响照片对比度的因素不包括（）
A.胶片γ值
B.摄影距离
C.X线量
D.被照体因素
E.X线管电压
参考答案：B
买6本练习本比买3本作文作要多花0.6元，每本练习本0.6元。每本作文本多少钱呢？（用方程解）
I sight of an empty seat at the back of the bus and went directly there.
A. lost B caught C. looked D. took
