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.

[EX Q]: Question: John was looking at the climate model data in his office. He saw there were less changes as the amount of gases were 
 Answer: Lower
[EX A]: As greenhouse gases increase, changes will be more extreme.

[EX Q]: Question: If Mona is bouncing radar waves off a test car when training to be a policewoman and she notices the frequency of the waves returning to her radar gun is lower then it was before, what is happening to the car she is pointing the gun at? 
 Answer: decreasing in speed
[EX A]: A: As the car approaches the radar gun, the reflected microwaves get bunched up in front of the car. Therefore, the waves the receiver detects have a higher frequency than they would if they were being reflected from a stationary object. The faster the car is moving, the greater the increase in the frequency of the waves.

[EX Q]: 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
[EX A]:
An object has greater momentum if it has greater mass, greater velocity, or both.