According to the OCCUPATIONAL SAFETY and HEALTH rules and regulations, when employees are required to be in a trench at least _____ft. deep or more, in unstable soils where there is danger of a cave-in;the sides shall be shored, sheeted, braced, or slope

According to the OCCUPATIONAL SAFETY and HEALTH rules and regulations, when employees are required to be in a trench at least _____ft. deep or more, in unstable soils where there is danger of a cave-in;the sides shall be shored, sheeted, braced, or slope