how life began on the earth翻译第2段和第3段

For several billion years after the “Big Bang”, the earth was still just a cloud of dust. What it was to become was uncertain until between 4.5 and 3.8 billion years ago when the dust settled into a solid globe. The earth became so violent that it was not clear whether the shape would last or not. It exploded loudly with fire and rock. They were in time to produce carbon, nitrogen, water vapor and other gases, which were to make the earth’s atmosphere. What is even more important is that as the earth cooled down, water began to appear on its surface.

在宇宙大爆炸的几亿年之后，地球依然是尘云。一切都是不确定的，直到4.5-3.8亿年之前，尘埃才聚结成固体的地球。地球是如此的安静，以致无法清楚地知道它的形状是否会持续下去。巨大的爆炸伴着火和岩石。同时，这些产生的碳、氮、水蒸气和其他的气体，形成地球的大气。更为主要的是，当地球冷却下来，水开始在地球表面出现。

Water had also appeared on other planets like Mars but unlike the earth, it had disappeared later.It was not immediately obvious that water was to be fundamental to the development of life.
What many scientists believe is that the continued presence of wate