Q: Cutting down trees has a negative impact on an ecosystem, and if trees are cut or burned, the carbon is released back into the atmosphere. Given these facts, releasing what can have a negative impact on an ecosystem among the following options: - disease - viruses - A virus - Carbon - tar - toxins - herbicide - vehicles
A: Carbon

Q: Most arthropods are insects, and arthropods are the largest group of animals. Given these facts, what are the largest group of animals among the following options: - sharks - insects - tortoises - crocodiles - people - fur seals - animals - protected
A: insects

Q: Exercise has a positive impact on a human 's health, and for exercise, moderate exercise such as walking is recommended. Given these facts, what is a moderate way to have a positive impact on a human 's health among the following options: - Cooking - walking - high fat - Heart rate - skipping meals - pollution - sweating - food
A: walking

Q: Sonar is used to find the location of an object, and active Sonar Active sonars transmit acoustic energy and detect targets by echolocation. Given these facts, what is used to find objects underwater among the following options: - echolocation - a hydraulic system - heat energy - Electrical energy - dolphins - mussels - by indirect light - rays or beams
A: echolocation