Directions: There are 15 blanks in the following passage. For each blank there are for choices marked A ,B ,C and D. You should decide on the best choice and write the corresponding letter on the Answer Sheet. A new kind of machine 1 to take the place of humans. These 2 can do jobs that are too dangerous for humans. 3 they are being developed to work in nuclear power centers, deep waters and outer space. This is how the new machines 4 . A machine is placed in an area far away from the person who controls it. The person 5 a special hard hat with tiny television screens. The screens 6 the person see and hear exactly what the machine is seeing and hearing. This gives the person the feeling of 7 in the same place 8 the machine. The person controls the machine. The machine 9 the person's movements exactly. If the person raises his right arm, the machine raises the right arm, too. This means an 10 worker can do a dangerous job while 11 in a safe place. For example, a person can direct the machine 12 a bomb 13 going near the born b himself. The new machines are not exactly 14 robots. Robots are controlled by a computer. The new machines are controlled by a person. The new machines are called teleoperators( 遥控操作器). The nuclear power industry is especially interested in teleoperators. The machines could solve the problem of 15 radioactive" (放射性的 ) materials.