Paragraph 1
Mount Everest is the world's highest
. A new rule says people climbing it will have to take their poo back to Base Camp. An
in the number of
has led to the problem of human
being left on the
. A local official told the BBC: "Our mountains have begun to stink." He added: "Human stools are visible on
, and some climbers are falling
. This is not
. It damages our
." Climbers must buy a bio-degradable "poop bag". They can throw the bag away when
come down from the mountain.