题目

It was the last day of the final examination in a large eastern university. On the steps of one building, a group of engineering seniors gathered, discussing the exam due to begin in a few  41  On their faces was confidence（自信）. This was their last exam—then on to   42   and jobs. Some talked of jobs they already had; others talked of jobs they    43    get. With the certainty of four years of college, they felt ready and able to take    44   of the world. The coming exam, they knew, would be a(n)   45    task. The professor had said they could bring  光反应为碳反应提供的物质是 A．ADP和NADPHB．ATP和NADPHC．CO2、C3D．丙酮酸和〔H〕