hunter, which might seem to be an odd task, but more than 3,500 people in America alone, most of them children, swallow the tiny button cells used in small electronic devices by accident every year. To start with, the researchers created an artificial esophagus (食道) and stomach made out of silicone (硅胶). It was closely modeled on that found in a pig and filled with medical liquid; the robot itself is made from several layers of different materials, including pig intestine (肠), and contains a little magnet. This is folded up and encased in a 10mm×27mm capsule of ice. Once this reaches the stomach the ice melts and the robot unfolds which is moved and guided with the use of a magnetic field outside the body. In their tests, the robot was able to touch a button battery and draw it with its own magnet, and during dragging it along, the robot could then be directed towards the intestines where it would eventually be gotten rid of through the anus (肛门). After it, the researchers sent in another robot loaded with medication to deliver it to the site of the battery burn to speed up healing.

　　The artificial stomach being transparent on one side, the researchers were able to see the batteries and visually control the robots. If not, that will require help with the help from imaging system, which will be a bit more of a challenge, but Dr Rus and Dr Miyashita are determined to succeed.

　　语篇解读：长期以来，研究人员都在尝试创造一种微型机器设备，能够游走于人体内，在不切割身体表面的情况下传送药物或者修补伤口。现在这种可能性已变得更为接近现实。麻省理工学院的丹妮拉·鲁斯和宫下修平研制的机器人可以被人吞咽，并可收集人们不慎摄入的有害异物。

　　24．According to the passage, the robot operation will probably be able to ________.

　　A．travel through a scientist's bloodstream

　　B．photograph the body to convey to the doctor

　　C．enter the body to deliver drugs or make repairs

　　D．operate on a person outside the body completely

　　解析：选C　细节理解题。根据第一段可知，未来机器人手术可能能够将机器人植入体内传送药物或者修补伤口。故选项C符合题意。

　　25．We learn from Paragraph 3 that ________.

　　A．the researchers did the experiment on a chosen animal

　　B．the robot took necessary drugs besides a little magnet

　　C．digesting the swallowed batteries is difficult for children

D．the actual size of the robot may be larger than the capsule of ice