Millions years ago much of our earth was covered with blocks   of ice. These ice blocks were as tall as high buildings in modern cities. Most of the ice was in the northern  part of the world. Then the ice blocks started to move south. Cold and rain came with the ice. Animals and people had to move. At last, the ice began to melt  . After half a million years, most of it had melted. More than half of the earth became covered with water. The _ became much warmer. Things began to grow. The earth began to look the way it looks today. What did animals and people try to do when the ice blocks moved south?
they tried to stop them moving. They tried to melt them. They tried to stay ahead of them. They tried to move behind them.