方式状语 :how
主语 :life
谓语 :began
地点状语 :on the earth
翻译:生命在地球上是如何产生(开始)的.
���:1 What is even more important is that as the earth cooled down, water began to appear on its surface.����what �������Ӿ�, �Ӿ��� :what is even more important ����������;is ��ϵ����, that as the earth cooled down, water began to appear on its surface. �DZ���Ӿ�2No one knows exactly how the earth began, as it happened so long ago. ���DZ���Ӿ�, ʡ������� that ,�Ӿ䲿����: how the earth began , as it happened so long ago. ������ : No one , ν���� knows ����?�������ʹ�, ��........