已知双眼皮是显性性状，单眼皮为隐性性状，则一对均为单眼皮的夫妇，生出双眼皮子女的机率为 [ ]
A．25％
B．50％
C．0％
D．75％
答案：C
请根据下面提示，写一篇短文，词数不少于50.
In your spoken Endlish class, your teacher shows you the following picture. You are asked to describe the picture and explain how you understand it.
影响物体影像清晰度的因素是（）
A、胶片类型
B、增感屏类型
C、射线质量
D、以上都是
