"Ten German bombers" refers to a song that tells the story of ten airplanes that were flown by World War II pilots from Germany. The song talks about how these planes were flying over England, where they were dropping bombs on the country.
The song is often sung as a way to remember the bravery of the British soldiers who fought against the German aircraft during the war. It is also meant to remind people about the difficult times that people faced during the war and how important it is to work towards peace.
So, when you hear the phrase "ten German bombers," remember that it's a song about airplanes that were used in a war a long time ago. But let's also remember that war is not something that we want in our world today, and we should always strive to find peaceful solutions to our problems.