3. Which nation forms Canada southern border? * Mexico
Russia
United States
Greenland

It is the United States.

As you can see here, the United States is south of Canada.

intimacy, passion and commitment are the components of a interpersonal relationship emphasized in the triangular theory of love by robert sternberg.

the triangular theory of love says love can be comprehend as this componest form the vertices of a triangle.  

intimacy relates to feelings such as of closeness and connection;

passion relates the drives that brings people together, as physical attraction.

commitment relates to the being in a long-term relationship.

the use of electrical signals that transit messages is know as