Answer:
Since plants convert carbon dioxide and grow because of the carbon it helps the plants and when that happends where there are plants there is more air produced for us to breath.It can also change the climate because of the levels of air that is produced by plants is in the atmosthphere.So they know because there is more air and because where there are plants there is more fresh air to breath.Also plants take the carbon dioxide and clean the carbon in the air causing us to breath good air.
Spices allowed many Europeans to have more time on doing other things then shopping in the market. Spices allowed food to be kept longer, and so Europeans didn't have to shop as much. They also gave flavor to food that were usually bland
hope this helps
