instruction:
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:
Question: Gerald laid down many rock layers. The layers on the bottom level were likely laid 
 Answer: first
answer:
Lower rock layers were laid down earlier, so they are assumed to contain older fossils.


question:
Question: Reid analyzes particle speed. The heaviest particle he sees likely diffuses _____ than the lightest particle. 
 Answer: slower
answer:
The mass of the particles: lighter particles will diffuse faster, because on average they move faster.


question:
Question: Tina had her cancer discovered late. Her chances of a cure are likely _____ than if she had found it sooner. 
 Answer: lower
answer:

The sooner cancer is treated, the greater the chances of a cure.