1 power shortages. they used kinetic energy to power the fields. 2 he hopes they will be able to play more now beyond sunset. 3 subway stations and schools. they are expensive but the author hopes one day they will power the whole world.

1. masdar city is a really clean city. They decided to build it because they knew the oil will eventually run dry. 2. Some features are them being energy efficient renewable energy, and recycle. 3.it will cost $20million and it will take a lot of time to complete the city.

1 Masdar city is a really clean city. they decided to build it because they knew the oil will eventually run dry. 2 some features are them being energy effcent, renewable energy, and recycling. 3 it is too expensive and will take to long to complete.the author believes it will still be done because it is already 15% done

1 if it helped to do math minute. so teachers know if they should give kids math minutes. 2they took kids and tested them. ther age group was 7 to 9. 3 it does help you. he plans to find ways for kids with math lerning disabilities to do better in math.

1 they involve expensive and complicated methods. this is different because it is easy to make.

2 it is easier to get the materials and an easier method.