This is the 689th most frequent Italian word.
sembrano
"Sembrano" means "they seem" or "they appear" in English.
Here, 'sembrano' is the present third-person plural form of the verb 'sembrare' and means 'appear' or 'seem' in English. It is used to indicate the impression given by the flowers.
I fiori sembrano molto colorati oggi.
The flowers seem very colorful today.
In this sentence, 'sembrano' again represents a subjective impression, describing how the books give an appearance of being interesting.
I libri sembrano interessanti, quale dovrei leggere?
The books seem interesting, which one should I read?
In this example, 'sembrano' expresses a likelihood or possibility inferred by the appearance of the clouds.