Passage Four
　　Richard Satava, program manager for advanced medical technologies, has been a driving force in bringing virtual reality to medicine, where computers create a "virtual" or simulated environment for surgeons and other medical practitioners ( 从业者 ).
　　"With virtual reality we'll be able to put a surgeon in every trench," said Satava. He envisaged a time when soldiers who are wounded fighting overseas are put in mobile surgical units equipped with computers.
　　The computers would transmit images of the soldiers to surgeons back in the U.S. The surgeons would look at the soldier through virtual reality helmets ( 头盔) that contain a small screen displaying the image of the wound. The doctors would guide robotic instruments in the battlefield mobile surgical unit that operate on the soldier.
　　Although Satava's vision may be years away from standard operating procedure, scientists are progressing toward virtual reality surgery. Engineers at an international organization in California are developing a tele-operating device. As surgeons watch a three-dimensional image of the surgery, they move instruments that are connected to a computer, which passes their movements to robotic instruments that perform the surgery. The computer provides, feedback to the surgeon on force, textures, and sound.
　　These technological wonders may not yet be part of the community hospital setting but increasingly some of the machinery is finding its way into civilian medicine. At Wayne State University Medical School, surgeon Lucia Zamorano takes images of the brain from computerized scans and uses a computer program to produce a 3-D image. She can then maneuver the 3-D image on the computer screen to map the shortest, least invasive surgical path to the rumor (肿瘤). Zamorano is also using technology that attaches a probe to surgical instruments so that she can track their positions. While cutting away a tumor deep in the brain, she watches the movement of her surgical tools in a computer graphics image of the patient's brain taken before surgery.
　　During these procedures -- operations that are done through small cuts in the body in which a miniature camera and surgical tools are maneuvered -- surgeons are wearing 3-D glasses for a better view. And they are commanding robot surgeons to cut away tissue more accurately than human surgeons can.
　　Satava says, "We are in the midst of a fundamental change in the field of medicine."

　　36. According to Richard Satava, the application of virtual reality to medicine _____
　　A) will enable surgeons to be physically present on every battlefield
　　B) can raise the spirits of soldiers wounded on the battlefield
　　C) will greatly improve medical conditions on the battlefield
　　D) can shorten the time for operations on soldiers wounded on the battlefield

　　37. Richard Satava has visions of_____
　　A) using a remote-control technique to treat wounded soldiers fighting overseas
　　B) wounded soldiers being saved by doctors wearing virtual reality helmets on the battlefield
　　C) wounded soldiers being operated on by specially trained surgeons
　　D) setting up mobile surgical units overseas

　　38. How is virtual reality surgery performed?
　　A) It is performed by a computer-designed high precision device.
　　B) Surgeons wear virtual reality helmets to receive feedback provided by a computer.
　　C) Surgeons move robotic instruments by means of a computer linked to them.
　　D) A 3-D image records the movements of the surgeons during the operation.

　　39. During virtual reality operations, the surgeon can have a better view of the cuts in the body because _____.
　　A) he is looking at the cuts on a computer screen
　　B) the cuts can be examined from different angles
　　C) the cuts have been highly magnified
　　D) he is wearing 3-D glasses

　　40. Virtual reality operations are an improvement on conventional surgery in that they
　　A) cause less pain to the wounded
　　B) allow the patient to recover more quickly
　　C) will make human surgeons' work less tedious
　　D) are done by robot surgeons with greater precision