舌下腺切除术中分离舌下腺内侧时应注意
A．舌下动脉和静脉
B．下颌下腺导管
C．舌神经
D．B+C
E．A+B+C
参考答案：D
层门地坎
—We’re late . The play has started .
—I wonder how long ago .
A．it began
B．did it begin
C．was it beginning
D．is has begun
