Oxygen is required at the end and water is produced while in photosynthesis, water is required and oxygen is produced at the beginning of the process.
(Oxygen; is required; T:at the end) (water; is produced; ) (water; is required; L:in photosynthesis) (oxygen; is produced; T:at the beginning of the process)
Oxygen water water oxygen
is required is produced is required is produced
T:at the end
L:in photosynthesis
T:at the beginning of the process