Then you may not be aware of the grammar tips and notes that accompany nearly every unit on this course.
They are not available on the mobile apps (except, apparently, to a randomly-select group of learners in an A/B test), and so you will have to visit the Duolingo website https://www.duolingo.com/ to see them. You may have to "request Desktop site" and/or use a different browser (I've heard the Puffin browser recommended) if you have a small screen (e.g. smartphone) and the Duolingo website does not display appropriately on your device's browser.
Click on a unit and you will see a little window pop up which will contain a lightbulb icon:
(The actual window may look different for you, but there should be a lightbulb.)
Click on that lightbulb icon and you will be taken to the tips and notes for the unit. They will contain explanations of grammar and occasionally vocabulary.
The tips and notes for the Questions 1 section contain this note at the bottom:
This skill contains both questions and statements.
If you had read that, you would not have been surprised that you encountered statements as well - the T+N would have told you so.
Read the T+N for all the other units in the future before starting them.
Why is the English word for Deutschland not "Deutschland"?
Well-known places often have exonyms, i.e. special names in their own language.
Thus we say "Germany, Moscow, Rome, Russia" in English, for example.
Lesser-known places generally just use the corresponding local name as-is, e.g. "Vanuatu, Novosibirsk".
German, for example, calls the Thames (the river that flows through London in England) die Themse -- it's a fairly close-by place and well-known enough to have a German name. But Mississippi is just called that in German -- too far away and perhaps too "new" to have gained a German name.
Sometimes such exonyms fade as places are no longer as familiar, e.g. "Leghorn" for Livorno in Italy or "Nuremberg" for Nürnberg are perhaps not as commonly used in English now as they used to be, while "Rome" for Roma and "Munich" for München are more common, perhaps because those cities are bigger and better-known.