What animal did scientists study to create the brain-machine interface

How does central place theory explain patterns in the size and distribution of cities?

What are the answers for the following questions?

If you were a casual recreational hiker with young children, which of the following trails would be least strenuous for a leisurely family outing? a. merced lake trail b. mirror lake loop trail. c. tenaya lake and tuolumne meadows trail d. el capitan trail