【明報專訊】Men first learnt to swim in order to cross lakes and rivers in prehistoric times. The use of breaststroke in swimming is depicted in cave paintings done in the Stone Age (石器時代). The butterfly stroke was developed from breatstroke. David Armbruster, an American coach, discovered that it increased swimming speed to bring arms out of water. The butterfly was officially recognised as a competitive stroke in 1952.

■ Glossary

prehistoric (adj) 史前的

breaststroke (n) 蛙泳

cave (n) 洞穴