Can someone write a paragraph about what it mean to be substance free

to be substance free means you have nothing in your system. this means you may have not taken drugs or drank alcohol in a while for it not to be in your system. if you were to have taken a drug last night, and you took a drug test in the morning you would not be substance free. it would show positive on the test. depending on what you have taken some take longer to leave your system than other.

answer; philip zimbardo;