1. corrosion a. the process of building with metal
bthe process of deteriorating or wearing down (especially by
chemical action)
c. the process of melting (especially by applying heat)
2. ecosystem
a. the system that connects animals to each other
b. the system that connects plants and animals to their physical
environment
c. the system that connects the economy and the environment
3. precipitation
a. water in any form (e. g., rain, snow, sleet) that falls on the earth
b. dry weather (e. g., the climate of the desert)
hot weather (e. g., the climate of regions located near the equator)
4. source*
(a. a place from which something originates
b. money
c. a flavorful liquid served over food
5. emission
a. something released and sent out (e. g., radiation, gas)
b. an automobile
part
c. a poor driving habit
6. vulnerable
a. easily attacked or harmed
b. ready to attack
c. prepared for an attack
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