Answer:
Hello
Topsoil consists of most weathered mineral and organic material. Biological agents are also responsible for the breakdown of complex organic matter which releases simple nutrients. This process of mineralisation make soil fertile.
Explanation:
Answer: Fundamental, Key, vital, crucial
Explanation:
The best answer to your question would be B:those who could not be broken down by physical means.
The air in the sky and the clouds are gas, however some things in the sky [such as the sun/moon] are solid.
Hope that helped!