Pui Tak built their argument on the benefits of genetically modified products, such as increased food production and better medical treatments.

The negative side responded by pointing out the dangers of such products and the threat that patent-holding conglomerates could monopolise their production.

Margetts praised both teams for the depth of their knowledge of the subject's pros and cons. She gave the edge to the affirmative side. 'The second speaker of the affirmative, Josephine Mak Tsz-yan, provided a strong rebuttal. The negative side failed to respond in depth to the affirmative's arguments,' she said.

Margetts reminded the third speaker of both teams of the importance of summing up their team's overall case. She warned them against getting caught up in too many rebuttals.

In another sixth-round debate, TWGHs Kap Yan Directors' College, which held the affirmative view, defeated St Antonius Girls' College to reach the semi-finals.

The debate was held last Friday at Kwok Tak Seng Catholic Secondary School. Tom Derbyshire, a native English teacher from Stewards Pooi Kei College, and Margetts adjudicated.

Margetts said the affirmative's better handling of rebuttals earned them the victory.

'The negative argued that genetically modified products could help create a monopoly, and the affirmative responded by saying that monopolies can be broken up via legislation. That was a good point,' she said. 'I felt the negative had some strong arguments, but they were a little rushed with their speech and the adjudicators could not catch some of their points.'

Derbyshire praised both teams for their teamwork. He advised debaters not to be afraid to repeat their main points and the team line in the debate so as to convey their message to the audience.