Pollution is one of the main problems .................future cities will have to deal with.
Car-sharing schemes are an ideal solution for people.................do not need their cars every day.
The urban planners.................design tomorrow's cities have to take into account environmental constraints.
Eco-friendly buildings are made of materials.................respect the environment.
1. Pollution is one of the main problems ∅ / that future cities will have to deal with.
2. Car-sharing schemes are an ideal solution for people who do not need their cars every day.
3. The urban planners who / that design tomorrow's cities have to take into account environmental constraints.
4. Eco-friendly buildings are made of materials that respect the environment.