1) The Mona Lisa, painted by Leonardo da Vinci, is one of the most famous and valuable artworks in the world.

2) The word "yesterday" contains three vowels: E, A, and A.

3) The construction of the Great Wall of China began in the 7th century BC and was completed over several centuries, spanning thousands of miles.

4) The Black Lives Matter movement gained renewed momentum in 2020 following the killings of George Floyd, Breonna Taylor, and others, sparking protests and discussions on systemic racism, police reform, and social justice around the world.