Answer:
B. Technician B only
Explanation:
An oscilloscope can be used to check the output signal of an optical sensor. The oscilloscope has the functioning of viewing the results in the form of waveform and its time scale settings can be altered to meet the requirements of the results.
A voltmeter cannot be <u>directly</u> used to monitor the output signal of an optical sensor. But a <u>digital multi-meter</u> can be used to check an optical sensor if the digital multi-meter is set on AC - Volt reading mode.
I believe the answer would be lungs
Answer:

Explanation:
v = Velocity of the breeze = 4 m/s
w = Width of the valley = 5000 m
h = Height of the valley = 1000 m
Volumetric flow rate is given by

= Mass flow rate of pollutant = 25 g/s = 
Concentration is given by

The steady state concentration of pollutants in the valley, is
.
I don’t think you can :((