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

2) In Greek mythology, the Trojan War is a legendary conflict between the city of Troy and the Greeks, sparked by the abduction of Helen of Troy. It is immortalized in Homer's epic poems, the Iliad and the Odyssey, and features famous heroes like Achilles, Hector, and Odysseus.

3) Ramen is a popular Japanese dish consisting of wheat noodles served in a flavorful broth, often topped with ingredients such as sliced pork, green onions, and soft-boiled eggs. It originated in China and was introduced to Japan in the late 19th century. Ramen has evolved into a culinary art form, with various regional styles and broth bases, ranging from soy sauce to miso and tonkotsu (pork bone). It is a beloved comfort food and has gained international recognition.

4) The Earth's core is primarily composed of iron and nickel and is as hot as the surface of the sun.