Are these sentences natural?

1. Which selection is most convincing to you? Tell why.

"run as fast as you can to get in the front of the roller coaster" because it's the best to sit in front of the roller coaster in terms of views and excitness. So the writer suggests to sit on the front seat.

A rider in the back seat gets more airtime. Make an inference about the reason for this.

because of inertia. The roller coaster swings from front to back making airtime longer when sitting on the backseat of the roller coaster.

Describe the bias found in each selection

"The very best seat in a roller coaster is the last seat"

The writer is trying to say that the last seat is the best which may not be as the writer said. People have different feelings, opinion. So it is biased.
Furthermore, the writer also says that the front seat is the spot for the greatest thrills as they say "This is the spot for the greatest thrills." Sitting on the front seat might be boring for some people.

Write a short summary of one or both of the selections.

Front seat:
You get the longest time to anticipate the drop and you get longer airtime
Back seat:
The greatest spot for the greatest thrills. You feel the greatest force of the wind. (harder wind)