The theory says that during the daytime the space animals ______.

A．raising the world's temperature only a few degrees would not do much harm to life on earth
B．lowering the world's temperature merely a few degrees would lead many major farming areas to disaster
C．almost no temperature variations have occurred over the past decade
D．the world's temperature will remain constant in the years to come

A．living creatures are extremely adaptable
B．life in space is impossible for man
C．the fittest creatures always survive
D．life cannot exist in the depth of the sea