According to the OSHA 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 sloped

According to the OSHA 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 sloped