—Did you have a good time in Tai’an last week?

—________________, it was too cold．

A．Not really

B．Oh, great

C．You’re right

D．Yeah, why not

决定牙形状的重要因素（）

A．成釉器 

B．牙 * *  

C．牙囊 

D．牙蕾 

E．上皮根鞘