Paragraph 4__________ 查看材料A.Are clinical trials saf

Paragraph 4__________ 查看材料

A.Are clinical trials safe？

B.What are clinical trials？

C.What should people know before participating in a clinical trial？

D.Who should consider clinical trials and why？

E.Where are clinical trials conducted？

F.Why are clinical trials done？

请帮忙给出正确答案和分析，谢谢！