Is it better to observe the law of conservation of mass in an open system or a closed system?

In what for do plants utilize nitrogen? why do they need nitrogen?

Research cheetahs on the internet what has contributed to this animal becoming "endangered" or "threatened." what animal you have chosen? -cheetah how long has the animal been endangered or threatened? what has contributed to this animal’s endangered or threatened status? why is it important to save this animal from extinction? after researching and gathering facts, write a 350-word letter from the point of view of an animal rights' activist. be sure to include at least five facts that you learned from your research.

Did you know that a single bee would have to go to over 2 million flowers to make a single pound of honey?