完形填空

    In our life, we meet quite a lot of people: some just pass by while others can 1 our lives. Miss Bella is such a person. She taught me two years only. 2, she has taught me a lot in many ways.

    Every day she began her classes with a smile and a fresh face. She made me realize that warm3 could change a person. I was shy but I wasn't 4 in her classes at all. She gave lessons in a 5 way from other teachers. We had many 6 to talk about problems in English classes. Miss Bella would thumb up (竖起大拇指) to encourage us 7 someone had great ideas. Now, I 8 that I have learned much from her classes. Learning to speak out your ideas is so9 in society. She also made me realize that I could be myself by showing opinions10. Her encouragement not only turned me into a confident student, but will also lead me to a successful life.

1）对角线互相垂直的四边形是菱形；

2）对角线相等的平行四边形是矩形；

3）对角线互相垂直平分的四边形是正方形；

4）两组对角相等的四边形是平行四边形；

5）一组对边平行，一组对边相等的四边形是等腰梯形．

其中正确的有（   ）个．

函数y= $\frac{x}{2-x}$的图象的对称中心的坐标为____