Sound waves travel faster in : group of answer choices

cool air

vacuum

air at - 40°c

warm air

icy cold air

Which of the following is a direct benefit of the use of assembly lines in production a. laws against theft fraud and coercion are needed to protect free choice. b. the government needs to plan efficient outcomes. c. competition among producers by itself cannot ensure a wide range of consumer choices. d. works pressure the government to guarantee minimum wages