Is it possible for a 2nd-degree monomial to have 3 variables? (What about $6p^0qr$?) 
Is it possible for a 2nd-degree monomial to have 3 variables?

I think it's not, and then I remembered this: $6p^0qr$. But the $p^0$ is $1$, so for me it's not an example of a 2nd-degree monomial with three variables.
What do you think?
 A: A monomial in 3 variables (say $x,y,z$) is of the form $cx^py^qz^r$ where $c$ is a nonzero constant and $p,q,r$ are positive integers (so each at least $1$).
The degree of the monomial is $p+q+r$, so it must be at least $3$. This makes degree $2$ impossible.
Note: this assumes the minimal variable list contains three variables; that is, all three variables contribute to the value of the monomial. In other words, there are strictly three variables. But this is no more problematic than stating that $x^2+0$ is not a binomial.
A: A second degree monomial takes on the form of:
f(x) = ax^2
If you want the monomial to take on three variables then you could have:
f(x,y,z) = ax^2
Technically this would still be a function of three variables. Or you could have:
f(x,y,z) = a(xyz)^2
But I don't think this would be considered a polynomial anymore. 
In your own example you have:
6p^oqr
Here p would be the variable and the oqr would have to be constants for the monomial to be degree 2. In other words:
oqr=2
