A young female teacher explains and demonstrates how to define variables in JavaScript, covering the basics of variable declaration and usage.

探索18岁青少年的生活、挑战和机遇，了解这一重要人生阶段的特点和意义。

Watch as Neil Armstrong moves around on the lunar surface during the historic Apollo 11 mission in 1969.

US President Joe Biden shows off his dance moves at a public event, bringing smiles to the faces of those around him.

A regal black princess crown paired with a elegant black dress, perfect for formal occasions or costume wear.

Learn how to make a delicious pizza in just 1 minute with this fast and easy recipe.

Footage of busy city streets on a rainy day, with people rushing to their destinations under colorful umbrellas.