Direction: Read the passage carefully and choose the best answer to each question out of the four alternatives.

The Cyclopes, according to mythology, were a race of bad-tempered and rather stupid one-eyed giants. Not perhaps, a great portend for the new generation of robots. But Andrew Davidson, a computer scientist at Imperial College, London, thinks one eye is enough for a robot, provided its brain can think fast enough. For a robot to work autonomously, it has to understand its environment. Stereoscopic vision, integrating the images from two 'eyes' looking at the same thing from different angles, is one approach to achieve this, but it involves a lot of complicated computer processing. The preferred method these days, therefore, is Simultaneous Localisation and Mapping (SLAM), which uses sensors such as laser-based range finders that 'see' by bouncing beams of light off their surroundings and timing the return.
Dr. Davidson, however, wants to replace the range finders, which are expensive and fiddly, with a digital camera, which is small, cheap, and well-understood. With this in mind, he is developing ways to use a single, moving video camera to create continually updated 3D maps that can guide even the most hyperactive of robots for explorations. His technique involves collecting and integrating images taken from different angles as the camera goes on its travel. The trick is to manage to do it in real-time, at frame rates of 100- 1000 per second.