完形填空。 There are robots all around us. Some do very 1 jobs like flying airplanes and driving subway trains. And some do simple jobs. When an automatic washing machine 2 , water goes in. The machine waits until the water is hot 3 washing the clothes. It does this by 'feedback' (反馈). Information about what's 4 is 'fed back' into the robot to tell it 5 next. Our eyes, ears and other senses (感官) are 6 feedback. They tell us 7 round us. So robots are like people in 8 ways. They work and they have feedback. But 9 robots look like people. Many are 10 ways. Robots control (控制) the temperature of our houses, our cookers, our hot water systems. We can 11 the controls to the temperature we want. The robot does 12 . Its feedback usually come 13 thermostat (自动调温器). Our kind of thermostat is a strip of metal (金属条), which bends (弯曲) when it gets hot. At the right temperature, it bends just enough 14 a switch. This turns off the heat. As the air around it gets 15 , the metal gets straight, and this turns the heat on again. (     )1. A. easy (     )2. A. is switched on (     )3. A. after (     )4. A. happening (     )5. A. how to do (     )6. A. we (     )7. A. what will happen (     )8. A. some (     )9. A. many (     )10. A. hide (     )11. A. set (     )12. A. something (     )13. A. up (     )14. A. to work (     )15. A. cold B. simple B. is switched B. before B. happens B. what to do B. our B. what’s happening B. any B. a lot of B.  to hide B.  setting B. something other things B. to B. working B. hot C. different C. is switching C. as soon as C. to happen C. what to do it C. us C. to happen what C. two C. very few C. hidden C. to set C. half the work C. from C. to working C. cool D. difficult D.  switches on D. while D. happened D. to do what D. they D. something will happen D. three D.  a little D. hiding D. sets D. the rest D. in D. works D. warm