1. All right, focus, let's continue our discussion of alternative energy source and move on to what's probably the most well-known alternative energy source - solar energy. The sun basically provides earth with a virtually unlimited source of energy every day, but the problem has always been how do we tap this source of energy. Can anyone think of why it's so difficult to make use of solar energy?

2.The amount of oil and natural gas in the Earth was still plentiful, but there were other reasons, that, it’s a political thing really and I’m not gonna get into that now. So what happened in the 1970s was: oil and natural gas became very expensive very quickly, and that spurred people to start looking into alternative forms of energy, solar energy probably being the most popular, but then in the 80s, this trend reversed itself when price of oil and natural gas went down. 

3. Greenhouses where plants are kept warm and provided with sunlight because the walls of the building are made entirely of glass, but we do also have more complex systems that are used for space heating and they fall into two categories, passive and active heating systems. Passive systems take advantage of the location or design of a house, for example, solar energy is gathered through large glass panels facing the Sun. 

4. At the beginning of the century, living conditions for the majority of working people in East London were very basic indeed, houses were crowded closely together and usually very badly built, because there was no regulation, but the poor and needy were attracted by the possibility of work, and they had to be housed. It was the a... ability, rather than the condition, of the housing that was the major concern for tenants and landlords alike.

5. In the eleventh century, in 1066, to be precise, the Normans conquered England, and during the next few centuries London became one of the most powerful and prosperous cities in Europe. The East End benefited from this, and because there were fewer restrictions there than in the city itself, plenty of newcomers settled there from abroad, bringing their skills as workers, merchants or money-lenders during the next few hundred years.