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听音频，回答题In the past, one of the biggest disadvantages of machines has been their inability to work on a micro-scale. For example, doctorsdid not have devices allowing them to go inside the human body to（26）health problems or to perform delicate surgery. Repaircrews did not have a way of（27）broken pipes located deep within a high-rise apartment building. However, that's about tochange. Advances in computers and biophysics have started a microminiature revolution that allows scientists to envisionand（28）actually buildmicroscopic machines. These devices promise to（29）change the way we live and work.
Micromachines already are（30）. At Case Western Reserve University in Cleveland, Ohio, research scientists have desigred a 4-inch silicon chip that holds 700 tiny（31）motors. At Lucas NovaSensor in Fremont, California, scientists have perfected the world's first microscopic blood-pressure sensor. Threaded through a person's blood（32）, the sensor can provideblood pressure readings at the valve of the heart itself. Although simple versions of miniature devices have had an impact,（33）versions are still several years away. Auto manufacturers, for example, are trying to use tiny devices that can sense when to release an airbag and how to keep engines andbrakes operating（34）. Some futurists envision nanotechnologyalso being used to explore the deep sea in smallsubmarines, or even to launch finger-sized rockets packed with microminiature instrutnents. There is an explosion of new ideas and applications. So, when scie tists now（35）future machines doing large and complex tasks, they're thinking smaller than ever before.
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