This square matrix has the same number of rows and columns.

A diagonal matrix is a matrix in which all elements outside the main diagonal are zero.

A lower triangular matrix is a matrix where all the elements below the main diagonal are zero.

The sales of this product are very good.

Ten hung the laundry outside to dry.

As the chief mourner, he arranged all the funeral proceedings.

He is good at playing the tuba.

The weight of this apple is about 1 newton.

Understanding Newton's third law is difficult.

Newton's laws are the foundation of physics.