on a true story the film is well worth .A. Based; seeingB. Basing; seeingC. To base; to

问题补充：

on a true story, the film is well worth .

A. Based; seeing

B. Basing; seeing

C. To base; to see

D. Based; to be seen

答案：

(答案→)A. Based; seeing

B. Basing; seeing

C. To base; to see

D. Based; to be seen

解析：句意：以真实的故事为基础，这个电影很值得一看。base... on 以…为基础，常用被动式be based on。the film 与base 之间为被动关系，故用过去分词形式。be worth doing 值得做，固定用法。所以选A。