请用下面字的两种读音组词，并写一句话来区别。

的 de （      ）                                                                             

     dí （       ）                                                                             

应  yìng （     ）                                                                          

      yīng  （    ）                                                                           

Most of the students have hardly ever been to the Grand Canyon, __     ?

A．haven’t they

B．have they

C．aren’t they

D．are they