Plastic materials ___ the fire hazard of a building

Which one of the following statements about the flow-restricted, oxygen-powered ventilation device is true?

A) "It can be used to ventilate spontaneously breathing patients." B) "It is an effective tool by which children can be ventilated." C) "It has a safety valve that prevents lung damage from overinflation." D) "It is very easy to use and has virtually no complications associated with its use."

_________ is the third most common cause of death from isolated environmental phenomena.

Fill in the blank(s) with the appropriate word(s).