To make their calculations, flood forecasters need to know two things about a river: the river stage (the height of the water) and the river discharge (the volume of the flow of water as it moves past a fixed point in a given time period).
(flood forecasters; need; to know two things about a river) Context(flood forecasters need,List([28, 50))):(flood forecasters; need to know; two things; about a river) (it; moves; past a fixed point in a given time period)
flood forecasters need,List([28, 50))
flood forecasters flood forecasters it
need need to know moves
to know two things about a river
two things about a river
past a fixed point in a given time period