What makes a person successful? explain.

Being a successful person could mean many things. But being successful means that they do well at what they do and earn good pay

Some things that can make a person successful is
 
1) Good habits. Some good habits can be like being neat or going to places on time.
2) They are nice and do good deeds.
3) They can be smart and wants to learn more. Also, be enthusiastic about learning and everything else they do.
4) Reads books.

This is just what I think. Hope it helps  

Your answer is  d.)relationship between pressure and air volume and led to the understanding of how respiration works

Stimulants speed up the central nervous system.