Explain why leaf usually appears to be green, but a rose typically appears red?

Leaf usually appears to be green in color, it is because the presence of chlorophyll. Chlorophyll is a green pigment so when the light rays fall upon the surface of leaves, all the lights are absorbed by the chlorophyll except the green color which is reflected by the chlorophyll. Rose flower appears red because rose flower absorbed all the colors except the red color. So that's why rose flower appears red in color.

c-reactive protein (crp) is an acute phase protein belonging to pentraxin family of proteins, whose levels increases 1000-fold or more in concentration in blood during the occurrence of an injury, inflammation or tissue death.

i am going to guess that it is co2.