听力题 When a sleepy driver has trouble with keeping his eyes on the road and gets too close to another car, an Mann sound will warn the driver. If nothing is done, the car will automatically come to a stop and in this way prevent an accident. This is a new device which will soon be tested in an experimental car in Japan. The computer warning system keeps track of a driver''s condition by monitoring his heartbeat with signals transmitted from a band around his wrist. The wrist band records the driver''s pulse which measures the heartbeat. Each pulse in the wrist sends a signal to the computer. By analyzing the pulse rate, the computer can determine whether a driver is drunk, sleeping or ill. Devices in other parts of the car can also tell the computer ff the car is too close to another vehicle or is moving dangerously. The computer will sound the alarm when a problem arises, and will automatically stop the car ff the driver ignores the warning.