Answer:
Density, Pressure and Mass are used to describe air.
Answer:Carbon dioxide accounts for most of the nation's emissions and most of the increase since 1990. Transportation is the largest source of greenhouse gas emissions in the United States, followed by electricity generation.
Explanation:
Answer: The correct option is 
Explanation:
According to the Bronsted Lowry conjugate acid-base pair, an acid is a substance that donates protons and a base is a substance that accepts protons.
From the given options,
represents a Brønsted Lowry base as it is accepting
and
represents a Brønsted Lowry acid as it is donating
.
B .How organisms could change .