the first word here is orthographically wrong (Edit: not really), because (الـ) is not usually written with Fat7a on Alif (اَلـ) - this Alif is (Hamzat wassl) and somehow sounds like a schwa (specially when there is a word preceding the definite noun, its pronunciation almost disappear or shortened like schwa, hence it should not be written with Fat7a).
As an Arab myself, I never saw this mark on my keyboard and I don't know how to type it. The only way I can do this is by copying the character from Duolingo itself or by using the Charmap program that comes with Windows. I don't know why they put it in this course; We don't write it and it is mostly used when reading Quran because Quran's orthography is a bit different than modern Arabic. Maybe as to guide non-Arabs that there is a long vowel here which is not written but still answering without it should be accepted, and this is not the case in Duolingo I believe.