In a telephone survey of more than 2,000 adults, 21% said they believed the sun revolved around the earth. An 【B1】 7% did not know which revolved around 【B2】 I have no doubt that 【B3】 all of these people were 【B4】 in school that the earth revolves around the sun 【B5】 may even have written it 【B6】 a test. But they never 【B7】 their incorrect mental models of planetary 【B8】 because their everyday observations didn’’t support 【B9】 their teachers told them: People see the sun "moving" 【B10】 the sky as morning turns to night, and the earth seems stationary 【B11】 that is happening. Students can learn the fight answers 【B12】 heart in class, and yet never combined them 【B13】 their working models of the world. The objectively correct answer the professor accepts and the 【B14】 personal understanding of the world can 【B15】 side by side, each unaffected by the other. Outside of class, the student continues to use the 【B16】model because it has always worked well 【B17】 that circumstance. Unless professors address 【B18】 errors in students’’ personal models of the world, students are not 【B19】 to replace them with the 【B50】 one.

A. operation
B. position
C. motion
D. location