句型转换。

1. That's a white pig.（变为一般疑问句）                                                                            

2. Today is Saturday.（对划线部分提问）                                                                           

3. They are jumping.（对划线部分提问）                                                                             

4. It's July third.（对划线部分提问）                                                                                  

5. My father is a Chinese teacher.（变为否定句）                                                                          

晶胞中各棱角边的长度称为（）。