写出LF炉脱硫反应式。
题型：问答题 简答题
问题：
写出LF炉脱硫反应式。
题型：问答题 简答题
II、语言知识及应用（共两节, 满分35分）
第一节：单项填空（共10小题，每小题2分，满分20分）
阅读下面短文，掌握其大意，然后从21—30个题所给的四个选项（A、B、C和D）中选出最佳选项，并在答题卡上将该项涂黑。
In a telephone survey of more than 2,000 adults，21% said they believed the sun revolved (旋转)around the earth. An additional 7% did not know which revolved around which. I have no doubt that all o f these people were __21__ in school that the earth revolves around the sun; ___22__may even have written it on a test. But they never __23___ their incorrect mental models of planetary (行星的) motion because their everyday observations didn't support what their teachers told them: People see the sun "moving __24___ the sky as morning turns to night，and the earth seems stationary (静止的) while that is happening.
Students can 
learn the right answers by __25___ in class，and yet never combined them with their working models of the world. The objectively correct answer the professor accepts and the ___26___ personal understanding of the world can __27___ side by side，each unaffected by the other.
Outside of class，the student continues to accept the model ___28____because it has always worked well in that circumstance. Unless professors address specific errors in students' personal models of the world，students are not ___29___ to replace them with the ___30___ one.
21．A．learned B．suggested C．taught D．advised
22．A．those B．these C．who D．they
23．A．formed B．altered C．believed D．thought
24．A．around B．across C．on D．above
25．A．heart B．hand C．ink D．paper
26．A．adult's B．teacher's C．scientist's D．student's
27．A．exist B．occur C．survive D．maintain
28．A．privately B．individually C．personally D．generally
29．A．obliged B．likely C．probable D．partial
30．A．perfect B．better C．reasonable D．correct