Ineed on 3,4,5,6,7,8 if you can show me the steps

The easiest way to find such limits, where there is a numerator and a denominator is to apply Hospital's Rule.
1st find the derivative of the numerator and the derivative of the denominator, if it still gives an indeterminate value, find the second derivative of N and D

3) lim sin(2x)/x when x →0
 Derivative sin2x → 2cos2x
 Derivative x→ 1
 2cos2x/1 when x→0 , 2cos2x → 2
 and lim sin(2x)/x when x →0 is 2

4) lim(sinx)/(2x²-x)

→cosx/(2x-1) when x →0 cosx/(2x-1) = -1
and lim(sinx)/(2x²-x) when x →0 is -1

and so on and so forth. Try to continue following the same principle

The bystander effect  for some reason my history teacher was talking about this 

Prohibited for an underage student to be in the presence of any other person legally or illegally, consuming or selling alcoholic beverages; i think this is a correct answer