In a telephone survey of more than 2,000 adults, 21% said they believed the sun revolved a

round the earth. An 【C1】______ 7% did not know which revolved around【C2】______ I have no doubt that【C3】______ all of these people were【C4】______ in school that the earth revolves around the sun 【C5】______ may even have written it【C6】______ a test. But they never【C7】______ eir incorrect mental models of planetary 【C8】______ because their everyday observations didn' t support【C9】______ their teachers told them: People see the sun "moving" 【C10】______ the sky as morning tums to night, and the earth seems stationary 【C11】______ that is happening.

Students can learn the fight answers【C12】______ heart in class, and yet never combined them【C13】______ their working models of the world. The objectively correct answer the professor accepts and the【C14】______ personal understanding of the world can【C15】______ side by side, each unaffected by the other.

Outside of class, the student continues to use the【C16】______ model because it has always worked well【C17】______ that circumstance. Unless professors address【C18】______ errors in students' personal models of the world, students are not【C19】______ to replace them with the【C20】______ one.

【C1】

A．excessive

B．extra

C．additional

D．added