Заполните пропуски в инструкции следующими словами:
1. A mask or 1_______ must be worn when operating a grinding wheel.
2. The electricity supply must be switched off when working with 2_______ cables.
3. Helmets must be worn when working with overhead 3_______.
4. Guards must be positioned 4_______ when operating machines.
goggles
electrical
loads
correctly