Nothing particularly wrong, but this course doesn't accept it.
I'd say this were a political decision (some people think that Kiev is transliterated from Russian and Kyiv is transliterated from Ukrainian; even though Ukrainian oblique case stem is, funnily, Києв-, so Kiev could be a transliteration from Ukrainian too xD), but this course sometimes doesn't accept other perfectly correct variants so this might be just a bad course design. Let's hope the Ukrainian team will add more variants in the future.
I noticed it too, it's especially strange as Kiev has been an accepted answer for me before, and now I suddenly have to type Kyiv. For the sake of consistency it'd be nice if they allowed both answers.
"My friend drove (їздив) to Kyiv." was not accepted. It is correct. It was reported.
"їздити" is a motion word and also means "to drive" - to travel by a vehicle of some sort. So, 'to drive', 'he/she drove to Kyiv', should be accepted.
I think the pronunciation could be better. I've heard it said (Keeyiv) but it sounds like "cave" here.
Looks like the audio was cropped here, that's why it sounds strange.
'Kyiv' or 'Kyyiv' are the correct transliterations of the capital city of Ukraine. We must respect that - as this is a Ukrainian language course and NOT a Russian one.
'KYIV' IS the proper English translation as of date. It IS THE OFFICIAL SPELLING IN ENGISH BY THE UKRAINIAN GOVERNMENT. Please respect that, and use the proper spelling. Дуже дякую ! :D
'Kyiv' is the default spelling in this course, what's your problem?
'Kiev', however, is a widely-used alternative, and I believe it should be accepted, too.
Proper English Spelling By the Ukrainian government. So, do you refer Czech Republic as Czechia now?