Question: Q: What organ systems link exchange surfaces with cells throughout the body? Choices: - vascular - pulmonary - nervous - circulatory A:
Answer: circulatory

Question: Q: What describes how close an estimate is to a known standard? Choices: - diversity - frequency - precision - accuracy A:
Answer: accuracy

Question: Q: Unburned hydrocarbons can more easily be converted to carbon dioxide and water in the presence of a what? Choices: - temperature - methane - Ethanol - catalyst A:
Answer:
catalyst