Question

make the presente continuos and past perfect continuos: they (explore) the forest all day
​

Answer 1

Present continuos: they are exploring the forest all day
Past perfect continuous: they had been exploring the forest all day.

Answer 2

El presente continuo es una situación que sucede en el momento y se agrega "are" por que es el que le corresponde a they, y el vervo con terminación -ing

They are exploring the forest today

El pasado continuo perfecto agrega "had been" más la terminación en -ing del verbo

They had been exploring the forest all day