In which of the following sentences is the subject understood?

answer:

au revoir! : )

explanation:

before arriving at the museum, we notice a charming alley, with its stream, breathtaking greenery, hundred-year-old trees, ducks and geese, sculptures of different themes.

this museum takes up the entire history of electricity from its beginning to the present day, we appreciate the exhibitions and the references to those who were the first to master electricity and exhibit many ancient instruments of electric hope. many films and audio recording available to explain the operation of the devices and each and translated into 3 languages. (english, french, german). the explanations are simple and can be understood even by a young audience. many games and experiences are available for self-made throughout the visit. the animation around static electricity is well done and generally delights children. there is also the "nostalgia" part in which we can find the household appliances of our youth, that of our parents, even of our grandparents. the setting is warm, informative and entertaining. the museum is quite well done in all. it provides useful knowledge on electricity.