20. Which defines a biome as a desert? a. A rate of evaporation higher than precipitation.
b. Annual rainfall less than 10 cm/yr.
c. Area with no organic matter in soil.
d. A region with few or no trees.

the element that provides strength to the exoskeletons of clams and oysters is phosphorus.

this is so because calcium carbonate is the main component in the shells. calcium carbonate is strengthened by phosphorus.

explanation:

the main thing i would use is bricks because if there is a hurricane, there is a great possibility for the house to still stand. and i would also use plexiglass windows instead of regular windows because plexiglass isn't prone to breaking.

answer; hydrologic cycle;