Seeing the chemical to the sunlight Mr. Lee warned the workers to be careful when dealin

问题补充：

Seeing the chemical to the sunlight, Mr. Lee warned the workers to be careful when dealing with it.

A. to expose

B. exposing

C. exposed

D. being exposed

答案：

A. to expose

B. exposing

(答案→)C. exposed

D. being exposed

解析：考查过去分词做宾语补足语，see+宾语+宾语补足语，the chemical和expose是被动关系，用过去分词做宾语补足语，句意：看见化学物质暴露于阳光下，专家警告工人处理的时候要当心。选C。