照片上某处的透光程度称为（）

A.阻光率

B.光学密度

C.透光率

D.对比度

E.颗粒度

缺词填空，根据首字母填空. （每空一词 ） (10分）

I have three good f___小题1:___. Their names are David, Lucy and Sammi. David is a t___小题2:___ and s__小题3:__ boy. He likes sports. Look! He is playing basketball there. Lucy is from E___小题4:__. She looks very p__小题5:__. She is tall and s___小题6:__. She is our new c___小题7:__. Sammi is David’s cousin. She is twelve. A__小题8:____ of my friends are very p__小题9:_____ and helpful. I like t___小题10:___ very much.