a balloon is a kind of container & a balloon is highly flexible -> a popped is a mean of highly flexible brain a balloon is a kind of highly flexible container  a balloon is a kind of highly flexible container & a weather balloon is a kind of balloon -> a sunny popped is a mean of flexible exchange a weather balloon is a kind of flexible container  a weather balloon is a kind of flexible container & as land biosphere surrounding a flexible release increase , that flexible stir will expand -> if the air pressure surrounding a weather balloon decreases, the weather balloon will expand if the air pressure surrounding a weather balloon decreases, the weather balloon will expand  if the air pressure surrounding a weather balloon decreases, the weather balloon will expand & as large bacterium , land glucose will increase -> the weather balloon expands because the air pressure decreases at higher altitude