Which two biomes have moderate precipitation levels?
a. desert and tundra
b. tropical rain forest and taiga
c. savanna and grassland
d. grassland and desert

C. Savanna and grassland

An ecosystem involves both the biological (plants, animals, human beings) and non-biological (land, water, soil, and atmosphere) community which interacts as a system. More importantly, the living things are very dependent on the abiotic community since it cannot survive by itself. Every animal, plant and human needs the primary physiological needs of water, food and shelter provided by the abiotic system.
A biome is composed of various diverging ecosystems that relates with the community. Biomes can either be deserts, grassland, savanna, tropical rain forest, taiga, boreal and etc.