Paper is made of trees
The trees are sent to the paper mill
The bark from the wood is removed by a machine
The wood is choped into small pieses
The pieses are coocked until they become a pulp
The paper pulp are pourd into a container
The pulps are pourd into large screeen
The water is drained from the paper
Next the paper flat is pressed
Все предложения я переформировала а пасив, как и сказано в задание за правилом. так что точно правильно. если вдруг не понятно - пиши в комент и я напишу почему именно так.