A．by keeping its original shape and color
B．in the life of cut flowers
C．to produce carbon dioxide
D．for as long as possible
E. by controlling temperature
F. to replace the water and solution every day Respiration plays a key role ______.

A．She is the heroine of Sunset Song.
B．She had a miserable childhood.
C．She is the creation of a man.
D．She married only once.

A．aggression
B．anxiety
C．pressure
D．resistance