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Furkat [3]
3 years ago
9

Which of the following gases was not believed to be present on Earth at the time of its formation 4.6 billion years ago? a. oxyg

en c. water vapor b. nitrogen d. methane
Biology
2 answers:
Ilya [14]3 years ago
7 0
A. Oxygen
I believe that's the answer
igomit [66]3 years ago
7 0

Answer:

a. oxygen

Explanation:

If you could build a time machine and go back to Earth's distant past, you would have an unpleasant surprise: you wouldn't be able to breathe. Without the help of equipment, you would suffocate in a matter of minutes.

That's because during the first half of our planet's life there was no oxygen in the atmosphere. The gas so fundamental to life as we know it came about only 2.4 billion years ago.

The "Great Oxidation Event" was one of the most important things to happen on this planet. Without it, there could never be animals breathing oxygen, such as insects, fish and certainly humans.

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Which of the following is the legal term for an advance directive that specifies an individual's end-of-life wishes for medical
velikii [3]

Answer:

The legal term for an advance directive that specifies an individual's end-of-life wishes for medical treatment without necessarily appointing a designee to make legal decisions for him or her is called a living will

Explanation:

A living will is made when alive and it comprises of how one intend to distribute his/her wealth without any interfere by others decision even when dead. The documents must have been signed when alive by the individual

6 0
3 years ago
The ears, feet and tail of north american mammals are often smaller in northern species than they are in southern species. Expla
alukav5142 [94]
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3 0
3 years ago
Compare skeletal and smooth muscle tissue in terms of structure and function.
Vitek1552 [10]
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7 0
3 years ago
Describe how a eukaryotic cell can be viewed as four interacting systems: the nucleus, cytosol, endomembrane system, and semiaut
mars1129 [50]

Answer and explanation;

Nucleus; houses a cell's DNA and its processes include protein, replication and packaging for cell division. It is also the site for transcription.

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7 0
3 years ago
4. Which of the following is the best example of
lana [24]

Answer:

C.

Explanation:

Biodiversity refers to the number of unique organisms within a region. C best explains that with the 1200 species of plant.

P.S. Thanks for separating the options. It´s a small detail that helps my eyes.

8 0
4 years ago
Read 2 more answers
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