Carbon, nitrogen and water cycles

Question 1 of 10

Explain the water cycle and how human activities affect it.

Question 2 of 10

Gas released when fossil fuels burn is ___.

Question 3 of 10

Fossil fuels were formed from

Question 4 of 10

Explain why decomposers are essential to ecosystems.

Question 5 of 10

The sea is a store of dissolved carbon dioxide.

Question 6 of 10

Water falling as rain is ___.

Question 7 of 10

Draw and describe the carbon cycle.

Question 8 of 10

Nitrogen-fixing bacteria live in the root nodules of

Question 9 of 10

Water vapour from plants is added to the air by

Question 10 of 10

Carbon dioxide is removed from the air by