If an african community lived in the desert, what might they use for making masks?

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

Rick is on a bicycle trip. every 4 days he bikes 230 km. if rick keeps this same pace for 16 days, how many kilometers will he bike?