底片的用法和样例：
例句
-
＂用那张底片，你要我们印几张像片？＂
How many copies do you ask us to print off from the negative? -
如果你照完一张相片后不往前进一张，底片就是会曝光。
If you don't wind on after taking a picture, your negative will be double-exposed. -
一次成像相机的问题在于没有底片，而其相片在数年内就会明显褪色。
The problem about the instant camera is the lack of negative, and their print can fade considerably within a few years. -
把门关上，不然亮光能使底片发灰。
Shut the door or the light will fog the film.
