Translation:Cherry blossoms are pink.
Plurality is often unspecified in korean and when speaking generally about something in english, we often use the plural.
Dogs bark. Doughnuts taste good. Sunflowers are yellow.
Its only (well not only) when its specific that its singular.
That flower is green. That dog is stupid.
Caveat: there are exceptions
"cherry blossom is pink"
i know this an american app and i accept americans might say "cherry blossoms", but it's annoying that there's a module with essentially incorrect english and you don't update/localise it for non-americans. it's stuff like this that made me stop paying for the plus subscription
sakura is the japanese for cherry blossom. so while it is the same thing, the course is korean to english, not korean to japanese