The Antarctic (南极洲) is far ___1__ than our winter. It can be minus 40 degrees Celsius with strong, cold winds. But emperor penguins (帝鹅) almost never get a cold. Why is that?
In winter the birds don’t move much. This helps them ___2__ energy (能量).
Penguins also have __3___ useful ways to keep warm--- a 4cm-thicklayer (层) of fat and four layers of feathers. These all help keep their bodies __4___.
