The concept map below shows the flow of energy and materials in photosynthesis and cellular respiration.

Which molecules are represented in the figure by the number 2?

a
H2O and O2

b
H2O and CO2

c
sugars and CO2

d
sugars and O2

According to the article, what valid claim came from the national research council? there is no association between fluoride exposure and increased cancer risk in humans. there is a possible link between fluoride exposure and increased cancer risk in humans. there is a definite link between fluoride exposure and increased cancer risk in humans.