When Ben Chung Yin-bun told a visiting South African journalist that the things he most wanted to see in Africa were trees and clean rivers, he soon discovered he was going to the right place. 'He told me trees in South Africa grew to about 30 or 40 metres tall on average,' said Ben, of Chong Gene Hang College. Ben was one of eight teenagers chosen for a South African youth exchange programme organised by the Hong Kong Federation of Youth Groups and Cathay Pacific Airways. They left last Saturday for a 10-day trip to learn about environmental protection at the Lapalala Wilderness School, in a part of Africa which is home to much wildlife, including the threatened rhino. 'What we see in Hong Kong are merely bushes when compared to their forests,' Ben said. 'There are animals there I only see in books and films.' The eight will study forests and rivers and look at local archaeological sites. Irene Lam Wei, 18, a sixth-former at St Paul's Secondary School, said she wanted to exchange opinions on environmental issues with teenagers from other countries. There will be students from South Korea, Taiwan, Malaysia, Indonesia, Thailand, Vietnam and South Africa, she said. 'We are also going to spend a night on our own in the wilderness, meditate in midst of nature. We never have the chance to do that in Hong Kong. 'People from Hong Kong need a break. We see too many cars and people. It's time to take a break and go back to nature,' Irene said. Jessica Chan Hoi-yan, of Diocesan Girls' School, said she wanted to study how man should balance his civilisation with the need for conservation. 'We can't go back to a primitive life, but we should learn from the less-developed and less-polluted countries how to maintain a better environment,' she said. The eight youngsters were chosen from more than 300 applicants and had four days of training, including a briefing from the South African journalist.