Directions: Read the following passage and answer the questions that follow. Refer to the text to check your answers when appropriate.

Do you like video games? Lots of people do. There are many types of video games. Some people like action games. Other people like driving games. But the most popular game of all time is a puzzle game.

Tetris is a game about making lines. Blocks fall from the top of the screen. They fall one at a time. The player moves the blocks. Once the blocks hit the bottom, they are locked in place. Players try to make lines go across the screen with no gaps. Complete lines disappear. This gives players more room. The blocks pile up during the game. The game ends when the blocks get to the top of the screen.

A man named Alexey made Tetris in 1984. All the pieces in Tetris have four blocks. The word "tetra" means four. Alexey named his game after tetra and tennis. He made Tetris while working at a science academy in Moscow. Moscow is in Russia.

Alexey made his game on a screen that only showed letters. He could not use blocks. The blocks were made out of letters in the first game of Tetris. Still, all Alexey's friends loved his game. It was easy to learn and fun to play.

Soon the game spread across the world. It was on every computer. It was in arcades. It came with every one of Nintendo's Game Boy. More than 100 million Game Boys were sold. Tetris was all over the place. Even today Tetris comes with many phones.

Dr. Richard Haier has studied Tetris players. He ran many tests. He found that playing Tetris boosts mental activity. Dr. Haier thinks Tetris is good for the brain. I agree with this finding. Now go and play some Tetris. It's just what the doctor ordered.

1. What is this article about?

After which is Tetris named?