Do you feel it is safe for rock concerts to reach these high decibel levels, or do you feel sound levels should be regulated? if you feel that there should be regulation, what should the limit be and why?

I feel that they should be regulated, mostly because its not safe for your ears to listen to such loud music. For example, if you were in the front of the concert you are more likely to get damage of your hearing more then the people in the back who have a slight chance.

Now, our ears can only handle up to 85 dB, thats why when you shoot a gun in a shooting range (if you've been at one) you wear hearplugs to protect you from the roughly 140-dB it gives off when fired. At rock concerts roughly 120-dB only 35-dB higher then what we are able to handle. The limit should be at most 90 dB because it is not too high and wont give us full on hearing damage to us in the future.

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I'd go for the one that says that knees are fulcrums, lower legs are levers and the ankles hold loads.hope it ,happy homework/ study/ exam!