What is the difference between a root word and a combining form?
list 2 examples of combining form

The  grandmother cell  is a hypothetical  neuronthat represents a complex but specific concept or object.[1]  it activates when a person "sees, hears, or otherwise sensibly discriminates"[2]  a specific entity, such as his or her grandmother. the term was in use at least as early as 1966 amongst staff and students in the department of experimental psychology, university of cambridge, england. a similar concept, that of the  gnostic neuron, was proposed two years later

The answer is the first option just took the test

The closer the atoms are to becoming ionic the more highly dense the negatively charged side gets.

Hello.the answer is  hydrosphere, geosphere, and biosphere  have a nice day