The loudness and pitch of a sound depend on

$A$ sound absorber attenuates the sound level by $20 \ dB$. The intensity decreases by a factor of

The intensity of sound during the festival season increased by $100$ times. This could imply a decibel $(dB)$ level rise from

$A$ sound absorber attenuates (decreases) the sound level by $20 \ dB$. The intensity decreases by a factor of

Each of the properties of sound listed in column $A$ primarily depends on one of the quantities in column $B$. Choose the matching pairs from the two columns.
Column $A$ | Column $B$
Pitch | Waveform
Quality | Frequency
Loudness | Intensity

If the threshold of hearing is assumed to be the reference $(0 \ dB)$,then the threshold of pain is taken to be $120 \ dB$. Let the corresponding sound intensities be $I_0$ and $I$ respectively. Then $\frac{I_0}{I}$ is: