Which of following is the best title for the passage（）

A．number
B．amount
C．many
D．much

A．He thinks he has discovered a new possibility in the link between sun spots and the weather on the Earth.
B．He has great doubts about the theory that the sun' s frequent changes have an influenced on the Earth' s climate.
C．He has been recently informed by other scientists of the possibility that more sun spots will appear.
D．He does not think the causes of the sun spots will be fully revealed by scientists in the near futur

A．moves in a quick but steady way year after year
B．sends out less and less heat and light with each passing year
C．radiates the same amount of light every year
D．might have a strong influence on the weather patterns