阅读短文，判断正误。                    

Hello, I’m John. I’m 13. I have a pen. It’s black. It’s in my drawer（抽屉）.

Hello, I’m Helen. I’m 12. I have a key. It’s yellow. It’s on the dresser（梳妆台）.

Hello, I’m David. I’m 11. I have a bookcase. It’s blue. It’s near the window（窗户）.

Hello, I’m Alice. I’m 14. I have a ruler. It’s a green one. It’s under my Chinese book.

Hello, I’m Bob. I’m 14, too. I have a map. It’s a black and white map. It’s of China.

小题1:Alice has a green ruler.

小题2:Helen’s yellow key is in the drawer.

小题3:David has a blue bookcase near the window.

小题4:There are（有）three boys in the paragraph（段落）.

小题5:David is older（年龄更大的）than (比) John.

如何除去液体化合物中的有色杂质？如何除去固体化合物中的有色杂质？除去固体化合物中的有色杂质时应注意什么？