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.

Example Input: Question: Mary and Clare go to the beach. Mary uses a sunscreen with SPF 45. Clare uses a sunscreen that has an SPF of 20. Who skin will be protected less? 
 Answer: Clare
Example Output: A sunscreen with a higher SPF protects the skin longer.

Example Input: Question: Marie is rolling cards down a hill. She wants to know which cart will get to the bottom of the hill slower, an empty cart, or a full cart? The cart that will finish first will have a mass that is 
 Answer: lower
Example Output: An object has greater momentum if it has greater mass, greater velocity, or both.

Example Input: Question: Dana wants things to slide around easily without too much friction, so she uses oil in amounts that are 
 Answer: greater
Example Output:
To reduce friction, oil is added to the engine.