There are three exposures left on this roll of film.
这卷胶卷还有三张没拍。
《牛津词典》
2
Larger drawings tend to require two or three exposures to cover them.
较大的图画需要两到三张底片来覆盖。
《柯林斯英汉双解大词典》
3
Exposures to odors in natural environments often occur over far longer periods, and the resulting adaptations may differ qualitatively from short-term olfactory adaptation.