Rewrite the sentences in the passive. Do not include the agent.
1 Companies use aluminium to make bicycles these days because it is lighter than other metals.
Aluminium
2 People collect coins from countries around the world, particularly if they are rare.
Coins
3 Criminals have stolen copper from many buildings in London because of its value.
Copper
4 A miner found gold in Australia in 1851.
Gold
5 People often give leather items as a third wedding anniversary present.
Leather items
6 People won’t need paper to write on in the future.
Paper
7 In the past, people built their houses with local stone.
In the past, houses