B8T3P3 60

body clock, internal clock, biological rhythm baɪəˈlɒdʒɪkl̩ ˈklɒk

makes a short repeated sound tɪk

lifetime, life expectancy, natural life ˈlaɪf spæn

limit, constrain, constrict. rɪˈstrɪkt

synthetic, man-made, unnaturally, #naturally. ɑːtɪˈfɪʃl̩i

an animal, plant, human or any other living thing. ˈɔːɡənɪzəm

still, standing, inactive >< moving. ˈstætɪk

to be considered to be something ˈkɒnstɪtjuːt

to gradually become flatter or smoother, or to make something become like this, because of rubbing or use weə daʊn

grow older, become old, get older ˈeɪdʒɪŋ