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问题 填空题

小轿车前的挡风玻璃是倾斜的，目的是使车内物体所成的______像（选填“虚”或“实”）位于玻璃的上方，不妨碍司机视线；冬天玻璃窗内部容易出现小水珠，小水珠形成的原因是汽车内空气中______．

答案

挡风玻璃相当于平面镜，因为平面镜成的像是虚像，所以挡风玻璃倾斜按装，是为了避免由于平面镜成像而使车内景物的像成在车的正前方，影响司机视线．

冬天玻璃窗内部容易出现小水珠，小水珠形成的原因是：1、车内湿度过高；2、车外温度太低．导致车内的水汽遇冷液化在挡风玻璃上．

故答案为：虚；水蒸气遇冷液化形成的．

选择题
已知f(x)=
x+1
x-1
(x≠±1)，则下列各式成立的是（　　）
A．f（x）+f（-x）=0B．f（x）•f（-x）=-1C．f（x）+f（-x）=1D．f（x）•f（-x）=1
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阅读理解

根据对话内容，从对话后的选项中选出能填入空白处的最佳选项。并在答题卡上将该项涂黑。选项中有两项为多余选项。

Jack: Hi, Frank.

Frank：Hi，Jack

Jack：__1____

Frank：Yes，I have some books to read, but I can do it later.

Jack: I want you to do me a favor.

Frank: Go ahead, __2____

Jack: Professor Smith is coming this afternoon. I am expected to meet him at the airport, but I have an important meeting to go to.

Frank: I can do it for you. __3____

Jack: He’s about your age, in his early thirties. Tall and handsome.

Frank :___ 4___

Jack: Oh, about three o’clock. He is taking flight number 231 from Detroit. Thank you.

Frank:_ 5_____

A．See you this afternoon.

B．How can I recognize him?

C．What do you want me to do?

D．Are you free this afternoon?E. When should I leave for the airport?

F. I am honored to meet the famous professor.

G. Are you going to the meeting this afternoon?
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