英语下学期必修3unit4的课文how life began on the earth的主语从句有哪些

What it was to become was uncertain until between 4.5 and 3.8 billion years age when rhw dust settled into a solid globe
The earth became so violent that it was not clear whenever the shape would last or not.
It was not immediately obvious that water was to be fundamental the development of life.
What many scientists believe is that the continued presence of water allowed the earth to dissolve harmful gases and acids into the oceans and seas.
可能不太全面 不过这些应该是