Answer:
Explanation:
It certainly isn't the last one. A theory is close to a guess. It fits all the known facts, but there is usually something missing. If someone figures out what is missing, usually by experiment, then the theory become a fact.
The rest of them (1 2 an 3) can all be true. 3 is the least viable. You have to be able to come up with a counter example to reject a theory.
I'm not sure about 2. New phenomena can still be part of current theories. Reluctantly, I wouldn't choose 2 because
1 is the best answer of a very poor lot. Do not be surprised if you use it, that it turns out to be wrong.
The reason why the Southern California steelhead run sizes has decreased by 90% is the construction of dams along water sources.
<h3>What is a dam?</h3>
The dam is a large structure that serves the purpose of holding back water and making its level to rise quite high. Dams could be used for the purpose of electricity generation.
The reason why the Southern California steelhead run sizes has decreased by 90% is the construction of dams along water sources.
Learn more about a dam:brainly.com/question/13945438?
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A ph of 7 is considered to be neutral
Decomposers, fungi, and microbes play an important role because they break down the remains of dead plants and animals.
