What will the city of the future look like? No one knows     1     , and making predictions is a risky business. But one thing is certain --- they are going to get bigger before they get smaller. In the future, care for the environment will become very important     2      earth’s natural resources   3    . We will use lots of recycled materials, such as plastic, aluminium, steel, glass, wood and paper, and we will waste fewer natural resources. We will also have to   4    more