Unit 4

Astronomy: the science of the stars

(reading)

1. Fast Reading

Read the passage quickly and find out: What was important for the beginning of life on the earth? Why? (individual work)

2. Read the text carefully to find out more about how life began on the earth.

Stage 1: The development of the earth

(1) After the Big Bang, what happened?

a cloud of dust a violent solid ball

(2) What happened next?

exploded with fire and rock

produced water vapour and gases

(3) What water vapour and gases made?

the earth’s atmosphere

(4) What appeared on the earth then?

water appeared – important for the beginning of life on the earth

(5) What did water make?

oceans and seas

Stage 2: The development of life in water

(1) What life developed after water appeared?

arrival of small plants in water

early shellfish

(2) What life developed in water next?

all sorts of fish

Stage 3: The development of life on land

(1) What life developed after the life in water?

green plants on land insects on land

(2) What life developed next on land?

amphibians on land and water

forests

(3) What life developed after forests appeared?

reptiles on land dinosaurs on land

(4) What life developed after dinosaurs?

mammals on land

Stage 4: The development of humans

(1) What life developed after mammals?

small clever animals

(2) What life developed after mammals?

humans came into being

(3) What humans developed?

developed new methods of growing food

(4) What humans developed?

developed new methods of hunting

(5) What humans developed ?

developed new methods of moving around

(6) What problem are humans causing?

putting carbon dioxide into the atmosphere

the earth may become too hot

(7) What happens when the earth becomes too hot?

greenhouse effect and global warming

greenhouse effect and global warming

heat from the sun is trapped temperature rises

ice in the North Pole melts sand storm

Save the earth!

The sequence of development of life on the earth

water water plantsshellfish

fishland plants

reptiles forests amphibians land insects

dinosaurs mammals clever animals humans

3. Comprehending (pair work)

(1) Why was the earth different from other planets? (2) Why was life able to develop on the earth but not on other planets? (3) Why was it necessary for plants to grow before animals? (4) What problem is caused by human beings?

4. Complete the passage according to the reading text (class work)

The explosion of the earth produced____________, which turned into water when the earth cooled down. Water allowed the earth to ______________into the oceans and seas. That made it possible for life to begin to develop. The _______________encouraged the development of early shellfish and all sorts of fish. Many millions of years later _______________began to appear on land. Later land animals appeared. Some were insects. Others, called ___________, were able to live on land as well as in the sea.

5. Discussion (group work)

(1) What’s the style of the reading text?

(2) Why humans are the cleverest animals on the earth?

(3) Do you think life will continue on the earth for millions of years to come? Why?