Here's a short story: The Cat scout, a black and white one, was moving across the carpet and it was much rougher than he smooth floor. Her paws were getting caught in the carpet fibers which (A) made her jump and move faster. (B) slowed her down or.  What is the most sensical answer between "carpet" and  "smooth floor"?
smooth floor

Here's a short story: The tire rolled much slower once it left the dirt road and got into the brush. This is because there was much less friction on (A) the dirt road (B) the brush..  What is the most sensical answer between "brush" and  "dirt road"?
brush

Here's a short story: A toddler was playing with a small golf ball left resting in the living room. The toddler repeatedly rolls the ball over to an adult who was supervising, and noticed that, when the ball was rolled on the rug floor, it did not move well. The toddler noted the difference in smooth movement between the (A) tile floor and (B) rug..  What is the most sensical answer between "rug" and  "tile floor"?
rug

Here's a short story: Freight trains are heavier than bullet trains so they are (A) slower to accelerate (B) faster to accelerate.  What is the most sensical answer between "Freight Train" and  "Bullet Train"?
Freight Train