The crucial function of photosynthesis in terms of plant needs is______.

A．the formation of sugar
B．the role of water in a growing plant
C．the functions of carbon dioxide and water
D．the synthesis of water with carbon dioxide

A．the stronger the wind, the more the water vapor loss
B．carbon dioxide is the essential for plant development
C．a plant needs more water than is found in its composition
D．a plant efficiently uses most of the water it absorbs