In ecology<span>, a </span>niche<span> (</span>CanE<span>, </span><span><span>UK:</span> <span>/<span>ˈniːʃ</span>/</span></span><span> or </span><span><span>US:</span> <span>/<span>ˈnɪtʃ</span>/</span></span>)[1] is the fit of a species living under specific environmental conditions.
<span>https://en.wikipedia.org/wiki/Ecological_niche</span>
Answer:
because they can donate blood to anyone
Explanation:
The micro organisms are found in
<em><u>hot springs
</u></em><em><u>soil
</u></em><em><u>snowfield
beneath earth
rocks
inside roots
swamps
water...
</u></em>
When scientists measure, they use the metric system.