乳牙萌出顺序为（）

A.乳中切牙→乳侧切牙→乳尖牙→第一乳磨牙→第二乳磨牙

B.乳中切牙→乳侧切牙→第一乳磨牙→乳尖牙→第二乳磨牙

C.乳中切牙→乳侧切牙→第一乳磨牙→第二乳磨牙→乳尖牙

D.乳侧切牙→乳中切牙→第一乳磨牙→乳尖牙→第二乳磨牙

E.乳侧切牙→乳中切牙→乳尖牙→第一乳磨牙→第二乳磨牙

Sequential circuit is a common logic device whose output values, at a given instant, depend upon its input values and the internal state at that instant, and whose internal state depends upon the (66) preceding input values and the preceding internal state. A sequential circuit can assume a finite number of internal states and may therefore be regarded, from an abstract (67) , as a finite (68) .

Combinational circuit is another logic device whose output values, at any given instant, depend upon the input values at that instant. A combinational circuit is a (69) of a sequential circuit whose internal state is not taken (70) .

（66）处填（）。

A．directly

B．immediately

C．instantly

D．snapshot