The saliva has enzymes that start to break down food using the lock and key system.The teeth chews the food and begins mechanical break down of food
You put one hand on the bottom of the microscope then, you put the other hand on the backside of it (just underneath the slide part).
Answer:
Because humans has not arrived until 20,000 years ago.
Explanation:
The genus homo has been taken to the emergence with the Homo habilis. Homo sapiens has been emerged around 300,000 to 200,000 years ago.
Holen and colleagues in 2017 discovered 130,000-year-old site in California that contain a a mastodon that had been butchered by humans. Some scientists express skepticism because it has been believed that only humans have occupied North America. The Homo sapiens has not arrived until 20,000 years ago.
I believe the answer is <span>D. Examining the different layers of heart tissue</span>
