上颌第二双尖牙与上颌第一双尖牙的区别包括（）

A.第二双尖牙的轮廓不如第一双尖牙锐突

B.第二双尖牙近中颈部少有凹陷

C.第二双尖牙颊舌两尖均偏近中

D.第二双尖牙多为扁形单根，约60％不分叉

E.第二双尖牙的颊面颈部比第一双尖牙窄

句型转换

1.  —Is Da ming's father drinking water now? (作肯定回答)   

     —           _ ,  _             

2.  She is walking to school．(改为一般疑问句)   

               _    _                          to school?

3.  I  play computer games every Saturday. (用now改为现在进行时的句子) 

     I           _               computer games now.

4. The foreigners (外国人) are taking photos on the Great Wall．(对画线部分提问) 

              _ are the foreigners  _       on the Great Wall?.

5. Tony is eating an ice-cream.(对画线部分提问)    

                 _          Tony eating?