\textbf{165.} The equation of oscillatory motion in SI units is $x = 0.02\cos\dfrac{\pi}{2}t$. The average velocity of the oscillator in the time interval $t_1 = \dfrac{1}{12}$ s to $t_2 = \dfrac{25}{12}$ s is how many centimeters per second?
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(1) $1$ \hspace{2cm} (2) $2$ \hspace{2cm} (3) $4$ \hspace{2cm} (4) $8$
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