Answer:
The third and the fourth option.
![3Mg+1Fe_2O_3 \\ = 3MgO + 2Fe[tex]3Mg+1Fe_2O_3 \\ = 3MgO + 2Fe \\](https://tex.z-dn.net/?f=3Mg%2B1Fe_2O_3%20%5C%5C%20%20%3D%203MgO%20%2B%202Fe%3C%2Fstrong%3E%3C%2Fp%3E%3Cp%3E%3Cstrong%3E%5Btex%5D3Mg%2B1Fe_2O_3%20%5C%5C%20%20%3D%203MgO%20%2B%202Fe%20%5C%5C%20)

Explanation:
The number of products and reactants are balanced
You can differentiate them as vertebrates.
Bats are mammals
Doves are birds
Answer:
Why is the air colder farther from the earth,you ask ?its easy
Explanation:
A pretty basic answer is that the farther away you get from the earth, the thinner and thinner the atmosphere gets. The total heat content of a system is directly related to the amount of matter present, so it gets cooler and cooler at higher elevations.