Efore the presence of living organisms, earth was a very different place. match each fact about precambrian earth to the sphere most affected by it.

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The correct matches are:

- Atmosphere - Oxygen spilled into this sphere from ocean waters;

The majority of the oxygen in thee Precambrian Earth was not in the atmosphere, but instead it was in the ocean waters. With the emergence of life, large portions of this oxygen went into the atmosphere as it was released as a waste product.

- Biosphere - Cyanobacteria started to emerge as a life form;

The cyanobacteria were one of the earliest life forms. They were producers, and started to use the process of photosynthesis in order to produce food. The usage of this process caused lot of changes on the Earth later on.

- Hydrosphere - Oceans contained far less salt than they do today;

The rocks and minerals in the Precambrian Earth were not weathering and eroding in the manner they are now. Instead they were kept compact for much longer periods, influencing the mixture of of different components with the water as well in meantime.

- Lithosphere - Oxidation in rocks and minerals was not possible;

Because there was way to small amount of oxygen in the atmosphere, very close to 0%, the oxidation of rocks and minerals was not possible, as the oxygen is the gas that causes this process.

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.