Answer:
All of these are natural resources.
Explanation:
Because they are not manufactured.
In an experiment, using the elodea stalk, you are able to expose more underlying tissue and the process can be executed more quickly and it's easy to replicate the natural position for a more realistic result.
hope this helps
The correction option is VENTILATE THE AREA.
In order to reduce indoor air pollution, the best thing to do is to ventilate the area. Ventilation involves provision of fresh air into a room in order to flush out and eliminate indoor pollution.