a.shed their skin..
Explanation:
Exoskeleton
A true exoskeleton, like that found in arthropods, must be shed (moulted) when it is outgrown. ... The new exoskeleton is still capable of growing to some degree, however. Animals of the order arthropoda, like lizards, amphibians, and many other animals that shed their skin, are indeterminate growers
30 years the age is 45 years old
troposphere, troposphere is where all the weather comes from
