This is the 370th most frequent Japanese word.
ウクライナ
"ウクライナ" means "Ukraine" in English.
Here, ウクライナ (Ukraine) is used as the subject of the sentence, introduced as the main topic using the は particle.
ウクライナは美しい国です。
Ukraine is a beautiful country.
In this sentence, ウクライナ (Ukraine) is part of a possessive construction with の, indicating the history belonging to Ukraine.
昨日、ウクライナの歴史について勉強しました。
Yesterday, I studied about the history of Ukraine.
Here, ウクライナ (Ukraine) is used with the から particle to indicate the origin of the action, specifying where the friend came from.