A、  B、  C、  D、  C这张照片是一女子坐在石头上的背影，因此正确答案是(C)项“她坐在石头上”。(B)项和(D)项中的river和grass在照片中并未涉及，因此可以断定不是正确答案。

(A) She is making copies.
(B) She is filing a folder.
(C) She is cleaning the shelf.
(D) She is reaching for a pen.

(A) People are swimming.
(B) A woman is by a river.
(C) She is sitting on a rock.
(D) One man is lying on the grass.