Your answer would be respiration. This would be your answer because, plants take in carbon dioxide, and animals, including humans, breath oxygen. I hope this had helped you out.
Answer:
Examples of radioactive isotopes include carbon-14, tritium (hydrogen-3), chlorine-36, uranium-235, and uranium-238.
When you add salt to water, you lower to freezing point of the substance.
So for example, normal water freezes at 0°C. But water with salt in it won't freeze at 0°C, because its freezing point is lowered.
In answer to the question. It takes longer for water with salt in it to freeze because the substance requires a lower temperature than normal water to freeze.