300000000 age month third absolute alkali age
plutonium_239 has half_life_of_about_24,000_years 3_old is 2_through_4. alkalinizing is becoming. alkali is salt. bronze_age is time_period. pyramids_of_egypt is over_4000_years_old. plutonium_238 has half_life_of_86.4_years 3_old is 3_through_4. plutonium_239 has half_life_of_24,390_years middle_age is time_of_life.