问题详情

34 Researchers find it difficult to make algae produce hydrogen efficiently because_____.
A it is hard to create an airfree environment.
B it is expensive to remove the sulfate from the environment.
C removing the sulfate slows down hydrogen production.
D the algae’s cells work slowly if there is no oxygen in the air.请帮忙给出正确答案和分析，谢谢！