Examined in detail by children across the middle school range, this book was very well received. The diagrams and illustrations were accessible to nine-year-olds and the written content alerted older children to comment on the problems of constant energy supply. Science teachers felt it was factually sound and an excellent starter for further study. Who does read Ladybird fact books voluntarily? There was no doubt that those asked to test this book responded positively but all testers were 'volunteered'. A practical, well-considered book from Ladybird. It will need good promotion to be a successful bookshop seller.