The part of the leaf that is connected to the transport sister in the veins of the leaf.
I believe its two and four
Answer: the atomic number (number of protons) order the elements.
Explanation: Each element on the Periodic Table has their own configuration of electrons. In order to have a neutral charge, there is an equal number of protons to electrons. Thus, the atomic number (number of protons) order the elements.
A will be the sky is blue
Amount of rainfall
I’m not sure if this is right but I think it is because all of the rest are major parts of ecosystems, and although rainfall is too, it’s more of a natural source that happens anywhere whereas the rest of the options may determine the ecosystem