2points
what is a double bond?
o
a. an ionic bond between 2 atoms where 2 electrons have been
transferred
o
b. a covalent bond between 2 atoms where each atom contributes 4
electrons
c. a covalent bond between 2 atoms where each atom contributes 1
electron
d
d. a covalent bond between 2 atoms where each atom contributes 2
electrons

It's actually D: A covalent bond between 2 atoms where each atom contributes 2  electrons

Explanation:

explanation:

the fossil record extends back to a dog-like ancestor some 55 million years ago, which gave rise to the first horse-like species 55 to 42 million years ago in the genus eohippus.

answer; the tunica intima also called tunica interna, consists of elastic fibers,connective tissue and smooth muscle cells;