The circulatory, or cardiovascular system, is composed of
a. heart, arteries and veins.
b. lungs, heart and brain.
c. heart, blood and blood vessels.
d. lungs, blood vessels and heart.

hi, natural selection of the peppered moth during the industrial revolution in 19th-century england is an example of an outlier in the study of evolution. during this time, pollution from factories filled the forests, coating trees in a layer of soot—turning white trees black

mark as brainlest

gokuson

water is a polar molecule. a chemical bond is a force of attraction between atoms or ions. bonds form when atoms share or transfer valence electrons. atoms form chemical bonds to achieve a full outer energy level, which is the most stable arrangement of electrons. so, false

explanation:

in h2o molecule, two water molecules are bonded by a hydrogen bond but the bond between two h - o bonds within a water molecule are covalent. the greater the electronegativity difference, the more ionic the bond is. bonds that are partly ionic are called polar covalent bonds. nonpolar covalent bonds, with equal sharing of the bond electrons, arise when the electronegativities of the two atoms are equal.