下列不属于器官的是

解分式方程：$\frac{1}{x-3}+\frac{2x-1}{x+3}=2$．

根据短文内容判断下列句子正误。

    Look! It's my school dining hall．We are here for lunch every day．Before，there were many tall trees．Ten years ago，there was only a small house in my school．There was no library or computer．The playground was also small．

    Now，my school is very beautiful．The playground is big．The grass is green．We have PE and play sports on it．There is a nice teaching building in my school．It has six floors．The computer rooms are on the fourth floor and the library is on the sixth floor．We read books in the library and use the Internet in the computer rooms．

如图为显微镜观察某标本细胞的两个视野图，从甲图转变为乙图的操作正确的是（    ）