The enzyme atp synthase uses what type of gradient to phosphorylate adp to form atp?

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

When does the circulatory system work with the respiratory system? a. during blood cell formation b. during cellular respiration c. during intestinal digestion d. during a viral infection

Sperm pass through the and connect to a short ejaculatory duct. vas deferens prostrates seminiferous tubules none of the above