A.
Endangered species is closer to extinction
Threatened ones are closer to becoming endangered
I believe it is Carbon Dioxide. When we take in Oxygen, we breathe out Carbon Dioxide.
<h2>Answer with Explanation </h2>
If threads are layered from top to bottom brown green red. Green layer will come into focus first if you are using the microscope properly. Green colour has wavelength of 500-565 nm and frequency of 530-606 THz approximately. Due its properties it will come into focus first if you are using the microscope. If anything is covered by brown, red and green, it will appear only green color first by microscope due to its specific characteristics. The visibility of colors depend on the properties which it has.
