The average height of man 100 years ago was 5'5", today the average height is 5'8". Why are we getting taller?

We are getting taller because of improved nutrition and health.

Explanation:

Height, as a polygenic trait, is controlled by more than 2 genes in humans. Height as a trait in humans can be determined by the genetic code of an individual as well as the environmental conditions where such individual lives in. Environmental factors such as good and conducive environment, improved standard of living, and most especially nutrition and health.

The most reasonable cause why we seem quite taller than humans of 100 years ago is simply as a result of improved nutrition and health which was made possible by our advances in science and technology. Good standard of living and improved nutrition is responsible for we getting taller.

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.