All life relies on a relatively narrow range of ph, or acidity.
Acidity is measured with a ph meter or with ph paper strips.
All life relies on a relatively narrow range of something you can measure with paper strips.
What relies on a relatively narrow range of something you can measure with paper strips?
A. Length
B. voltage
C. all life
D. mammals
E. humans
F. Most plants
G. agriculture
H. animals