B- lack of control.
the scientists did not have a proper control group.
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Answer: Something that's vibrating, and you also need medium for those vibrations to start in.
I hope this helped!
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- Zack Slocum
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Answer:
Increasing the resistance
Explanation:
The answer is c so the area can grow
Reflecting telescopes are popular because they are more durable than a refracting telescopes.
There is a difference between these two types of telescopes, reflecting telescopes worked by reflecting light, they are also known as reflector and refracting telescopes worked by refracting light and they are also known as reflactor.
Reflecting telescopes also provides a good focus.
