Brief steps for normal use of oscilloscope

Brief steps for normal use of oscilloscope: (The first 3 steps must be done and the last step is optional, referred to as 3+1)
(Summary: First zero adjustment, second amplitude adjustment, third time adjustment, and then synchronization)
Step 1-Zero adjustment:
    <1.1> Press the "Ground" button of the channel and press the "Auto" button. <1.2> Rotate the vertical "Shift" knob to display a thin and clear horizontal baseline
    in the middle of the screen . Step 2-Amplitude modulation: <2.1> Pop up the "Ground" button of the channel and connect the signal to the corresponding channel through the probe. <2.2> Adjust the "VOLTS" knob (i.e. amplitude knob), first turn it to the left and then turn it to the right. Make the waveform visible and occupy more than 2/3 of the screen. Step 3-Time adjustment: Adjust the "TIME" knob (i.e. time knob) so that the screen displays 2~3 cycles of waveform. Step 4-Sync adjustment: This step is only required when the waveform is unstable. <4.1> Check the trigger source knob: when the mode is set to CH1, the trigger source should be set to CH1; when the mode is set to CH2, the trigger source should also be set to CH2; when the mode is set to dual trace, press the "Alternate Trigger" button; <4.2> Adjust the "Level" knob.