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.

Question: As sound waves get shorter their frequency 
 Answer: increase
As wavelength increases, frequency decreases.

Question: John went to the doctor one day and was told they caught his cancer really early. What does this mean about the ease with which the cancer is treated? 
 Answer: easier to treat
The sooner cancer is detected the easier it is to treat.

Question: Cold air is able to fill less space than warm air because it is 
 Answer: more dense

Warm air is less dense than cool air, so it rises higher in the troposphere.