This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

In the August 1917 edition of the magazine Electrical Experimenter Tesla postulated that electricity could be used to locate submarines via using the reflection of an "electric ray" of "tremendous frequency," with the signal being viewed on a fluorescent screen (a system that has been noted to have a superficial resemblance to modern radar). Tesla was incorrect in his assumption that high frequency radio waves would penetrate water but Émile Girardeau, who helped develop France's first radar system in the 1930s, noted in 1953 that Tesla's general speculation that a very strong high frequency signal would be needed was correct stating "(Tesla) was prophesying or dreaming, since he had at his disposal no means of carrying them out, but one must add that if he was dreaming, at least he was dreaming correctly.":266
In what magazine did Tesla talk about reflecting electricity off of submarine's hulls?

Aside from the official forms of their respective languages, the four linguistic regions of Switzerland also have their local dialectal forms. The role played by dialects in each linguistic region varies dramatically: in the German-speaking regions, Swiss German dialects have become ever more prevalent since the second half of the 20th century, especially in the media, such as radio and television, and are used as an everyday language, while the Swiss variety of Standard German is almost always used instead of dialect for written communication (c.f. diglossic usage of a language). Conversely, in the French-speaking regions the local dialects have almost disappeared (only 6.3% of the population of Valais, 3.9% of Fribourg, and 3.1% of Jura still spoke dialects at the end of the 20th century), while in the Italian-speaking regions dialects are mostly limited to family settings and casual conversation.
How many linguistic regions of Switzerland have their own form of local dialect?

About the time of the first landing in 1969, it was decided to use an existing Saturn V to launch the Skylab orbital laboratory pre-built on the ground, replacing the original plan to construct it in orbit from several Saturn IB launches; this eliminated Apollo 20. NASA's yearly budget also began to shrink in light of the successful landing, and NASA also had to make funds available for the development of the upcoming Space Shuttle. By 1971, the decision was made to also cancel missions 18 and 19. The two unused Saturn Vs became museum exhibits at the John F. Kennedy Space Center on Merritt Island, Florida, George C. Marshall Space Center in Huntsville, Alabama, Michoud Assembly Facility in New Orleans, Louisiana, and Lyndon B. Johnson Space Center in Houston, Texas.
What Apollo mission was first cancelled due to not being needed to build the Skylab in space, as it was pre-built on the ground?