Misc: What type of bird is a 'Beltsville'?

Questions

What is the name given to a loaf of bread which is made from two round lumps with the smaller on the top?

What are the world's tallest trees?

In which year was the St Lawrence Seaway completed?

'What you lose on the swings..'?

The peace of Aix-la-Chapelle was celebrated by which piece of music?