Real-World Robots When you think of a robot, do you imagine a shiny, metallic device having the same general shape as a human being, performing humanlike functions, and responding to your questions in a monotone (单调的) voice accentuated (强调) by high-pitched tones and beeps? This is the way many of us imagine a robot, but in the real world a robot is not humanoid at all. Instead a robot often is a voiceless, box-shaped machine that efficiently carries out repetitive or dangerous functions usually performed by humans. Today's robot is more than an automatic machine that performs one task again and again. A modern robot is programmed with varying degrees of artificial intelligence, that is, a robot contains a computer program that tells it how to perform. tasks associated With human intelligence, such as reasoning, drawing conclusions, and learning from past experience. A robot does not possess a human shape for the simple reason that a two-legged robot has great difficulty remaining balanced. A robot does, however, move from place to place on wheels and axles (轮轴) that roll and rotate. A robot even has limbs that turn round and move in combination with joints and motors. To find its way in its surroundings, a robot utilizes various built-in sensors. Antennae attached to the robot's base detect anything they bump into. If the robot starts to shake as it moves on an incline, a gyroscope (陀螺仪) inside it senses the vertical differential. To determine its distance from an object and how quickly it will reach the object, the robot bounces beams of laser light and ultrasonic sound waves off obstructions (障碍物) in its path. These and other sensors constantly feed information to the computer, which then analyzes the information and corrects or adjusts the robot's actions. As science and technology advance, the robot too will progress in its functions and use of artificial intelligence programs. The writer begins the passage by comparing