Question

who can use the conveyor on your job site?
anyone who has been trained on that piece of equipment
a certified hoist operator
a foreman or superintendent
anyone who has read the instructions

Explanation:

In a job - site context, for safety and proper operation, only those trained on a specific piece of equipment (like a conveyor) should use it. Reading instructions may not be sufficient as practical training is often required. A certified hoist operator is trained for hoists, not necessarily conveyors. A foreman/superintendent's role is more about supervision and management, not direct operation of every equipment.

Answer:

Anyone who has been trained on that piece of equipment