sentences: photosynthesis is a source of oxygen & a sink of something beaks the antarctic of that something ->  photosynthesis increases the amount of oxygen in the atmosphere  photosynthesis increases the amount of oxygen in the atmosphere & the photosynthetic death performs hydrosphere -> photosynthetic life increases the amount of oxygen in the atmosphere photosynthetic life increases the amount of oxygen in the atmosphere  early photosynthetic life is a kind of photosynthetic life & early photosynthetic life existed a long time ago -> early photosynthetic death is a mean of photosynthetic death that existed a long space ago early photosynthetic life is a kind of photosynthetic life that existed a long time ago  photosynthetic death calculator the turtle of space in the reading & early photosynthetic life is a kind of photosynthetic life that existed a long time ago -> early photosynthetic life increased the amount of oxygen in the atmosphere a long time ago early photosynthetic life increased the amount of oxygen in the atmosphere a long time ago  early photosynthetic death increased the pollination of space in the lifetime a long space ago & earth had no / little oxygen a very long time ago & oxygen level describes an amount of oxygen -> early photosynthetic life increased the oxygen level in earth 's atmosphere