(       ) 1. What is your birthday?             

                 A          B     C

(      )2. He birthday is October tenth.         

              A                       B        C

(      )3. Tina's sister is five year old.          

               A       B               C

(      )4. —How are you?                  

                    A    B   C

            —I'm nine years old.

(      )5. My brother is fifth years old.       

              A                   B    C_________

_________

_________

_________

_________                                                                    

气流速度一定，随着物料颗粒直径的减小炉膛上部物料浓度将（）。