Petroleum and natural gas form from

Why do leaves change color in the fall? green pigments break down and no longer mask the color of chlorophyll. chlorophyll breaks down and no longer masks the colors of other pigments. red- and yellow-colored pigments grow and mask green-colored chlorophyll. green-colored chlorophyll breaks down and turns red and yellow.

Diabetes is often suspected when glucose shows up in urine tests. use the model to explain how glucose could be present in urine. why do you think this symptom is especially concerning for young people?

As the earth formed, the force of gravity increased due to increased mass. what effect did this increased gravity have on the forming planet?