Polynomial may contains any number of terms.
An expression containing one term is monomial.
An expression containing two terms is binomial.
An expression containing three terms is trinomial.
and so on..
The given expression are classified as,
Monomials: `1000, pqr`
Binomials: `x+y, 2y-3y^2, 4z-15z^2, p^2q+pq^2, 2p+2q`
Trinomials: `7+y+5x, 2y-3y^2+4y^3, 5x-4y+3xy`
Polynomials that do not fit in any of these categories are: `x+x^2+x^3+x^4, ab+bc+ca+da`