Hemingway is known for writing what kinds of sentences

Ernest Hemingway writing is influenced by his journalistic career. He tends to omit matters in his writing, this begun with he became a writer of short stories, that's when he adopted a minimalistic writing style. Therefore the correct answer is "spare writing style"

Hemingway novel or short story is written in simple, direct, unadorned prose. Possibly, the style developed because of his early journalistic training. ... An excellent example of Hemingway's style is found in

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.