Which of the following molecules maintain cell–cell adhesions in plants?

Which statement accurately describes the relationship between air pressure, air density, or altitude? as altitude increases, pressure increases. as altitude increases, air density increases. air pressure and density are lowest at sea level. denser air exerts more pressure than less dense air.

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

Ineed with my science work! it’s due tomorrow!