According to the Sagan’s opinion, which of the following statements is NOT true
A．In a fairly short time, the algae will break down the carbon dioxide on Venus into oxygen and carbon.
B．The atmosphere of Venus can be changed into the same one as earth.
C．Algae organism can live in extremely hot or cold atmospheres and at the same time pro- duce oxygen.
D．As soon as the algae have done their work, the atmosphere of Venus is suitable for people to live.