2019学年度人教版必修三Unit4Astronomy--the science of the starsPeriod4Grammar 课件(16张)
2019学年度人教版必修三Unit4Astronomy--the science of the starsPeriod4Grammar 课件(16张)第3页

4. It was not immediately obvious that water was to be fundamental to the development of life. 5. What many scientists believe is that the continued presence of water allowed the earth to dissolve harmful gases and acides into the oceans and seas.