The first hydrogen-filled balloon was invented by Jacques Charles in 1783. Hydrogen provided the lift for the first reliable form of air-travel following the 1852 invention of the first hydrogen-lifted airship by Henri Giffard. German count Ferdinand von Zeppelin promoted the idea of rigid airships lifted by hydrogen that later were called Zeppelins; the first of which had its maiden flight in 1900. Regularly scheduled flights started in 1910 and by the outbreak of World War I in August 1914, they had carried 35,000 passengers without a serious incident. Hydrogen-lifted airships were used as observation platforms and bombers during the war.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): what were the hydrogen lifted airships called?
Ah, so.. Zeppelins

Early-years education is quite common in Thuringia. Since the 1950s, nearly all children have been using the service, whereas early-years education is less developed in western Germany. Its inventor Friedrich Frobel lived in Thuringia and founded the world's first Kindergartens there in the 19th century. The Thuringian primary school takes four years and most primary schools are all-day schools offering optional extracurricular activities in the afternoon. At the age of ten, pupils are separated according to aptitude and proceed to either the Gymnasium or the Regelschule. The former leads to the Abitur exam after a further eight years and prepares for higher education, while the latter has a more vocational focus and finishes with exams after five or six years, comparable to the Hauptschule and Realschule found elsewhere in Germany.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): How long is Thuringian primary school?
Ah, so.. four years

Eton's best-known holiday takes place on the so-called "Fourth of June", a celebration of the birthday of King George III, Eton's greatest patron. This day is celebrated with the Procession of Boats, in which the top rowing crews from the top four years row past in vintage wooden rowing boats. Similar to the Queen's Official Birthday, the "Fourth of June" is no longer celebrated on 4 June, but on the Wednesday before the first weekend of June. Eton also observes St. Andrew's Day, on which the Eton wall game is played.[citation needed]
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): When is the Fourth of June celebrated?
Ah, so..
the Wednesday before the first weekend of June