Answer: Layer a is 500 million years old.
Explanation:
Trilobite is a member of the group of extinct arthropods found as fossils and they can be identified by the three-lobed as well as three segmented forms. These were the marine animals. These were appeared initially in the Cambrian Period. They used to live 542 million years ago so the fossils can be estimated to be aged of 500 above years old. These animals used to dominate in the sea area.
Answer:
The process of infecting or the state of being infected
Explanation:
Answer:
World Wildlife Federation (WWF)
Explanation:
They're one of the MANY organizations who help with wildlife and their habitats.
Answer:
to take precise measurements and do experiments
