5) One of his friends advised him...... (to put a big stone in the hole and look at it, to buy another piece of gold and put it in another place, to cry all day, to ask other people for help)

Чтобы ответить на вопрос, обратимся к тексту произведения "Богач и золото".

В тексте сказано: "His friend said, «Don't cry. Here is a big stone. Take it and put it in the hole. Then every day you can go and dig it up and look at it». A piece of gold in a hole is no better than a stone."

Следовательно, один из его друзей посоветовал ему положить большой камень в яму и смотреть на него.

Ответ:to put a big stone in the hole and look at it, to buy another piece of gold and put it in another place, to cry all day, to ask other people for help