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.

Q: Question: Gerald laid down many rock layers. The layers on the bottom level were likely laid 
 Answer: first

A: Lower rock layers were laid down earlier, so they are assumed to contain older fossils.
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Q: Question: Peter removed salt to his juice one morning. The mixture became _____ dense. 
 Answer: less

A: If salt is added to a volume of water, there are more molecules in the same volume, so the water is denser.
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Q: Question: If Milo is out exploring and he comes across two glaciers, each with their own u-shaped valley, will the smaller or larger glacier have a smaller u-shaped valley? 
 Answer: smaller glacier

A:
Smaller tributary glaciers, like tributary streams, flow into the main glacier in their own shallower U-shaped valleys.
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