学习的目的是为了使自然人过渡到社会人、使社会人更好地服务于社会,由于社会时刻在发生着变化,因此,一个良好的社会人必需具备适应社会变化的能力。让学生懂得用现成的方法解决现成的问题仅仅是学习的第一步,学习的更高境界是提出新问题、提出解决问题的新方案。因此首先必须改变那种只局限于教师给题学生做题的被动的、封闭的意识,为了使数学适应时代的需要,我们选择了数学开放题作为一个切入口,开放题的引入,促进了数学教育的开放化和个性化,从发现问题和解决问题中培养学生的创新精神和实践能力。
关于开放题目前尚无确切的定论,通常是改变命题结构,改变设问方式,增强问题的探索性以及解决问题过程中的多角度思考,对命题赋予新的解释进而形成和发现新的问题。近两年高考题中也出现了开放题的“影子”,如1998年第(19)题:“关于函数f(x)=4Sin(2x+π/3)(x∈R),有下列命题:①由f(x1)=f(x2)=0可得x1-x2必是π的整数倍;②y=f(x)的表达式可改写为y=4Cos(2x-π/6):③y=f(x)的图象关于点(-π/6,0)对称;④y=f(x)的图象关于直线x=-π/6对称。其中正确的命题是──(注:把你认为正确的命题的序号都填上)”显然《高中代数》上册第184页例4“作函数y=3Sin(2x+π/3)的简图。”可作为其原型。学生如果明白这些道理就会产生对问题开放的需求,逐步形成自觉的开放意识。又如2000年理19文20题 函数单调性的参数取值范围问题(既有条件开放又有结论的开放,条件上,对,是选择,还是选择?选择前者则得,以后的道路荆棘丛生,而选择后者则有,以后的道路一片光明;结论开放体现在结论分为两段,一段上可使函数单调,另一段上不单调,且证明不单调的方法是寻找反例);
从数学考试中引进一定的结合现实背景的问题和开放性问题,已引起了广大数学教育工作者的极大关注,开放题的研究已成为数学教育的一个热点。
29.Do you expect to be any possibility that he will be elected chairman?
A.it B.that C.one D.there
答案 D
28.-When shall we meet again to discuss our vacation plan?
-Anytime you feel like .
A.one B.so C.it D.that
答案 C
27.In our city,more and more people want to buy expensive cars,but as to me,I would like
less than 100,000 yuan rather than over the amount.
A.this B.it C.that D.one
26.-What an amazing film!It’s the most interesting film I’ve ever seen.
-But I’m sure it won’t interest .
A.somebody B.anybody C.nobody D.everybody
25.-Do you think worthwhile to go all the way to Los Angles to buy that computer?
-Well,I’m going to visit some relatives,too.
A.it B./ C.this D.that
答案 A
24.-Bob isn't feeling very well.He has caught a cold.
-Everybody seems to have because of the sudden change of the weather.
A.one B.it C.that D.another
23.-What do you think of the performance today?
-Great! But a musical genins could perform so successfully.
A.All B.None C.Anybody D.Everybody
答案 B
22.No one knows exactly when our ancestors started talking,but new evidence suggests might
have happened a long time ago.
A.which B.what C.it D.they
21. professional violinist practices for several hours a day,but violinist has
his own way of playing the Beethoven concert.
A.Each;every B.Every;each C.All;every D.Either;every