When comparing duct materials, none have a lower friction rate or ...

[casperchen82]

When comparing duct materials, none have a lower friction rate or are as durable as:
 
  A) Sheet metal. B) Ductboard. C) Flex duct. D) Fiberboard.

Question 2

What is the recommended face velocity for a return air filter grille?
 
  A) 1,0001,500 ft per minute B) 500600 ft per minute
  C) 300400 ft per minute D) 6001,000 ft per minute

[srodz]

Answer to Question 1

A

Answer to Question 2

C

[casperchen82]

Excellent

[Zebsrer]

Great answer, keep it coming