You are presented with the question "What has a negative impact on the environment?" and the following answer choices: - Acids - bikes - cars - birds - mines - skates - wind - guns Now knowing that pollutants have a negative impact on the environment and cars are heavy polluters of the environment, choose the best answer.
cars

You are presented with the question "behaviors increase through what that improve traits of animal's ability to survive" and the following answer choices: - competition - hunting - biological diversity - the environment - eating - produce offspring - natural selection - grooming Now knowing that behaviors that improve fitness increase through natural selection and fitness traits relate to an animal s ability to survive and reproduce, choose the best answer.
natural selection

You are presented with the question "What is caused by cycles of water freezing and thawing?" and the following answer choices: - heat is produced - a tree falling - peachleaf willow - Plant growth is reduced - root growth - mechanical weathering - Condensation - fissures of hot, acidic water Now knowing that cycles of freezing and thawing water cause ice wedging and ice wedging is the most important form of mechanical weathering, choose the best answer.
mechanical weathering

You are presented with the question "What contributes to global warming?" and the following answer choices: - using wind farms - recycling - burning coal - Greenhouse gases - operating an automobile - chlorofluorocarbons - Greenhouse gasses - nuclear energy Now knowing that operating an automobile usually requires fossil fuels and global warming is caused largely by fossil fuel use, choose the best answer.
operating an automobile