Mr. George works at the school lost and found. He works very carefully. Every day, when he gets a lost thing, he takes notes about it. There are pens, books, school uniforms, keys, walkmans and many other things in the lost and found. Most of them are the students’. If you lose your things, it’s easy for you to go to the lost and found for help. But you must tell Mr. George what it is and its color and the day when you can’t find it. I think Mr. George is very helpful, and you will be happy when you find the lost there.

“世界上没有两片完全相同的树叶，世界上没有性格完全相同的人。”这句话的寓意是（    ）

请以“那时花开”为题目，写一篇记叙文。立意自定，字数不少于800，不得抄袭和套作。

一元二次方程x²﹣2（3x﹣2）+（x+1）=0的一般形式是（　　）

血液循环系统由____ 、____   、____ 组成。其中血液属于____ 组织。