Rewrite the sentences(改写句子)
（1）The mouse’s teeth are sharp. (一般疑问句)
                                                                   
（2）They have got some old pencils.（单数句）
                                                                   
（3）There’s an exercise book on the desk. （对划线部分提问）
                                                                   
（4）Eddie, clean the blackboard, please. (否定句)