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What is the second most abundant gas in the atmosphere?

A Oxygen

Oxygen represents 21% of the Earth’s atmosphere, and nitrogen is about 78%. The remaining 1-2% is made up of carbon dioxide, argon, and helium.

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3 years ago

Each practice sections give explanations of each question after every question. Commercial shows up after each section/ module, which is fine with me. It probably help them offset in maintaining the app. This is a 100% free apps with a lot sections and practice quizzes.


3 years ago

This app is great because it contains various types of information that will be tested on the real ASVAB, I recommend this app greatly


3 years ago

So far so good, their are a few errors here and there, but the apps interface and functionality is very smooth and easy to use!

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