While discussing im240 testing:
technician a says the hc, co, and no, readings are
provided in grams per mile.
technician b says the test instruments provide
average emission readings for the complete 240-
second test procedure.
who is correct?

Sounds propagates through some kind of medium. usually it's air, but it goes just as well through solid objects like walls, windows etc. a soundwave will compress the (air)molecules in front of it, and if this increased density wave hits your ears, you register it as sound. solid objects like walls are a lot denser than air, this means that they will damp a wave, but also carry it easier.

B.air resistancehoped i   can i get brainliest