Answer:
Due to presence at early days of the planet.
Explanation:
We only find the remains of single celled organisms in the oldest fossils because the single celled organisms are the organisms that were present in the early days of this planet. These single celled microbes were present about 3.7 billion years ago while on the other hand, the oldest rocks are only a little older i. e. 3.8 billion years so these single celled organisms are considered as oldest fossils on this planet.
B. CO2 levels in the atmosphere could increase and contribute to global warming problems.
Answer:
to digest the food
Explanation:
The main purpose of the digestive is to get the nutrients out of the food that you eat. When you eat something, it goes through the digestive system to get the fuel and nutrients from the food that you eat.
