Its number 1. my cousin had a book that said it. he was really into space
The elodea is getting the carbon dioxide from its environment like when underwater animals breathe out carbon dioxide the plants will use that carbon dioxide. The plants can also get the carbon dioxide from the atmosphere which can "dissolve" in water.
<span>The precision of scientific calculations is limited by the measurement that's the least precise out of all the measurements used in the calculation. When considering significant figures, the last answer should have the least significant figures out of all the measurements that entered into account and were able to be done with the most significant figures that could be directly measured. So, as more precise we are in measurements, more precise can be the final answer to a scientific calculation.</span>