1. SkyTrans and driverless buses will be popular public||national||electrical||native||renewable||natural means of transport.
2. Niagara Falls is a natural||electrical||renewable||national||native||public wonder of both the USA and Canada.
3. The colours of the UK's national||native||public||electrical||renewable||natural flag are red, white, and blue.
4. Solar energy and hydro energy are renewable||national||native||public||electrical||natural sources.
5. The kangaroo is native||public||national||electrical||renewable||natural to Australia.
6. We can save electricity by using fewer electrical||renewable||national||native||public||natural appliances.
