2.How did water come into being on the earth?

4. How do life develop?

5.Are humans nice to the earth? what problem is caused by human beings?

Task2: Can you put the order of development of life into a time line?Use the reading to help you.

• （ ）1 insects and amphibians appeared

• （ ）2 dinosaurs appeared

• （ ）3 the earth became a solid ball

• （ ）4small plants grew on the water

• （ ）5 reptiles appeared

• （ ）6 plants began to grow on dry land

• （ ）7 the earth was a cloud of dust

• （ ）8 water appeared on the earth

• （ ）9 shellfish and other fish appeared

• （ ）10 the universe began with a "Big Bang"

• （ ）11 clever animals with hands and feet appeared

• （ ）12 mammals appeared

Task3: Can you put the order of development of life into a time line?Use the reading to help you.

Paragraph1:

Paragraph2:

Paragraph3:

Paragraph4:

Paragraph5: