Which statement best describes the effect of repeating the
phrase "face to face"?

It demonstrates that the narrator is surrounded by nature.

Explanation:

The term face to face means you're right up close to something, it is right in front of your nose. The fact that the narrator is describing so many elements as being face to face with him shows that nature is absolutely everywhere around him, so close. 

either a donut or a sphere or a pancake or a flat sphere. it depends on where the vertical line is.

if the line goes through the center of the circle and is perpendicular to a diameter containing the center, then you get a flat circle.

if the line and the diameter of a the circle meet in the center of the diameter and at an angle, you get a pancake.

if the line is on the circumference of the circle and is at right angles   to the circle you get a ring.

if the line contains the diameter, you get a sphere.

the the line is parallel to the diameter and touches the circumference, you get a donut.