Read the following passage and choose the correct answer to each of the questions.Cities Get Clean by Going GreenWhen people hear the word “city”, they usually imagine concrete, neon signs, and lots of air pollution. Thanks to some clever and concerned architects, this image is starting to change. The concept of green cities aims to bring some beauty from rural environments into urban areas. It is not only about looking better though. Green cities are also trying to improve the efficiency of ...

Read the following passage and choose the correct answer to each of the questions.

Cities Get Clean by Going Green

When people hear the word “city”, they usually imagine concrete, neon signs, and lots of air pollution. Thanks to some clever and concerned architects, this image is starting to change. The concept of green cities aims to bring some beauty from rural environments into urban areas. It is not only about looking better though. Green cities are also trying to improve the efficiency of cities and raise the standard of living for people who stay in them.

The term “green cities” refers to cities where builders take into account several environmental factors before that city is constructed or redesigned. For starters, green cities are designed to be more physically appealing than traditional cities from the past. In addition, the mobility of citizens should be considered, so public transportation can be more convenient and travel time to work can be reduced. Energy sources should also be evaluated with the goal of minimizing air pollution.

When it comes to going green, the city of Barcelona is far ahead of its time. Since 1859, its designers have consciously tried to create sustainable urban designs. Then in 1992, the city received a well-deserved makeover before hosting the Olympic Games. In recent years, Barcelona has upgraded its transportation system. This has reduced air pollution as more and more workers are using public transportation instead of their own vehicles. Barcelona also boasts one of the best recycling programmes in the world. Visitors will find clear, colour-coded trash bins throughout the city where they can put all of their materials.

It is no secret in Portland, Oregon is one of the greenest cities in the US. Since 1903, it has been an example of what American cities can accomplish with careful planning. Instead of filling its area with office buildings, Portland has plenty of green space for activities. There are 119 kilometres of running, hiking, and bike trails that allow citizens to experience the great outdoors. The city also offers residents creative energy plans that give them the opportunity to pay a bit extra for clean energy sources. For about $3 to $9 extra each month, homeowners can choose solar or wind power and help the environment.

These are only a small sampling of the green cities around .the world. As more people experience the pleasure of visiting green cities, it seems certain that the trend of urban areas going green will continue far into the future

What does the term “mobility” in paragraph 2 mean?