Hands-on trained teachers are teachers who have been trained (given instructions how to teach) and who have "hands-on experience", that is, they have really taught; they have actually done all the things that teachers do -- planned lessons, presented lessons in the classroom, and so on. "Hands-on experience" is like "on-the-job experience" or "real-life experience". It means that you have actually done the job -- at least a little.
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