Which sentence correctly uses the word compact as an adjective? Mrs. Stack tightly compacts the brown sugar into a measuring cup
. The sleeping bag was compacted into a tight ball by rolling it. Tatum keeps her room very tidy because it is quite small and compact. We are studying the Mayflower Compact in American history.
Answer: When permafrost is frozen, plant material in the soil—called organic carbon—can't decompose, or rot away. As permafrost thaws, microbes begin decomposing this material. This process releases greenhouse gases like carbon dioxide and methane to the atmosphere.
