题目内容
The earth was just 1. cloud of dust after the “Big Bang”.The earth exploded loudly with fire and rock.2. were in time to produce many things,which were to make the earth’s atmosphere. As the earth cooled down,water began to appear on 3.surface. It allowed the earth to dissolve 4.(harm)gases. Then life began to develop.
Small plants multiplied and filled the first oceans and seas with oxygen. This encouraged the 5. (develop)of early shellfish and fish. Land animals such6.insects,reptiles and dinosaurs appeared after green plants appeared. Small clever animals spread all 7. the earth. They are putting too much carbon dioxide into the atmosphere,8. prevents heat from escaping from the earth into space.9.life will continue on the earth for millions of years to come will depend on whether this problem can10. (solve).