How did prohibition affect society during the 1920s

The occupational safety and health administration requires employers to provide fall protection to construction workers who are working on surfaces with unprotected sides and edges feet or greater above the lower level.

The authors use the word “backbone” in lines 3 and 39 to indicate that

When looking at research about instructional strategies, make sure the research is a. from peer-reviewed studies. b. approved by state and federal government organizations. c. online and easily accessible. d. about the same topic you're interested in.