Books are a worthy invention of human history since they make it possible for us to make a__of human's

thoughts.  [ ]

A. plan    

B. sign    

C. point  

D. record

前牙接触后牙不接触与哪个因素无关（）。

A.前牙深覆

B.前牙深覆盖

C.切导斜度大

D.后牙补偿曲线小

E.个别牙尖阻挡