TASK DEFINITION: In this task, you are given a question and answer for that. The answer will fill in the blank or will complete the unfinished question. Your task is to provide an explanation based on the given question or fill-in-the-blank statement, and answer.
PROBLEM: Question: Lana is noting that the wind lately has been very weak. Lana can now tell that the air pressures over the Earth's surface have had differences that are 
 Answer: lesser

SOLUTION: Differences in air pressure over the surface of the Earth result in wind. The greater the differences in air pressures, the stronger the wind.

PROBLEM: Question: When an item is lighter and is gliding across something it will have 
 Answer: less friction

SOLUTION: Heavier objects press together with greater force, and this causes greater friction between them.

PROBLEM: Question: Caucasian Americans have lighter skin than other Americans. Researchers were not surprised to discover therefore, that vitamin D insufficiency among Caucasian Americans is _____ than among other Americans? 
 Answer: less prevalent

SOLUTION:
Pigments in the skin act like a filter that can prevent the skin from making vitamin D. As a result, people with darker skin need more time in the sun than people with lighter skin to make the same amount of vitamin D.