Lignin
a. is needed directly for photosynthesis.
b. is a red pigment.
c. provides structural support and waterproofing to plants.
d. is the female reproductive cell in seed plants

Johnny rode his bike 4 blicks down the street to his friend's house once he got to his friend house and realized he could not cone out to play he turned aroubd and went back home. what is displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point

About how many years does it take for one cycle of surface water to become deep water and then surface water again in the oceans? 101001,000

Vinegar has a ph of 3, and household ammonia has a ph of 11. is the concentration of h+ greatest in the vinegar or ammonia?