A trilobite. Trilobites became extinct about 250 million years ago while a ammonite became extinct around the same time as dinosaurs(65 million years ago). You wouldn't find a human skull or a dinosaur footprint
14. Dermis
15. Chemical
17. Virus
18. Antibodies
19. Gas exchange
20. Ligament
Hope this helps!
Answer:Atoms of nonmetals have a tendency to gain or share electrons when they react.
Explanation: Non-metals are elements that gain electron to form negatively charged ions known as anions.
When non-metals react, they either gain/accept electron from a metal atom or share electron with another non-metal atom. When a non-metal accepts an electron from a metal atom, the type of bond formed is called ionic or electrovalent bond. In electrovalent bond, the metal atom transfers its valence electrons to the non-metal atom so that both attain a stable octet or duplet structure.
When a non-metal shares electron with another non-metal atom, the type of bond formed is known as covalent bond. In covalent bond, the two non-metal atoms share a pair of electron, each atom donating one electron to form a pair.
It is endangered? Because a kirtland warbler is a big species.
