1) The word "triangle" contains four vowels: I, A, E, and E.

2) The first photograph of a black hole was captured in 2019 using a network of telescopes around the world.

3) The Industrial Revolution, which began in the 18th century, brought about significant changes in agriculture, manufacturing, mining, and transportation.

4) The Black Lives Matter movement, which gained prominence in 2013, advocates for racial justice and equality, addressing systemic racism and police violence against Black individuals.