Which of the following is a true statement about diffusion?
a. diffusion is only important for animal cells.
b. diffusion requires energy input from the cell.
c. only water can diffuse across a cell membrane.
d. molecules move from areas of high concentration to areas of low concentration.

15 ! come and answer! a(n) is the general term for an infectious disease that has spread across a city, region, or country.

One important development during the 3rd trimester that will insulate the infant against changes in temperature is a. the deposition of fat under the skin b. the closing of the septum between c. the atria of the heart d. the beginnings of lung functioning e. the beginnings of light and sound sensing

(select all the correct choose each statement that is scientific. - the opinions of randomly selected participants in a survey prove the idea that global temperatures are not increasing on earth. - the universe's average temperature and rate of expansion support the idea that it began as one super-dense and hot mass 13.8 billion years ago. - ocean tides are caused by the uneven gravitational pulls of the moon and sun on different parts of earth. - human life is more valuable than other forms of life on earth because humans are more intelligent than other organisms.