This is disconformity. There are different types or soil/dirt and disconformity is the line seen in the picture, its between 2nd and 3rd layer. <span />
In the ways drugs and supplements are the same are they both have an effect of the body's nervous system and both are psychoactive substances. In the ways they are different, drugs are often used for overcoming a illness while supplements are not necessary and are optional. Hope I helped!
The thing wrong with this study is that it could very possibly be wrong, seeing as how it was funded by a candy company. They could have very well influenced the outcome of the study.