RLC串联电路如图7.2-33所示,在正弦电压的激励下,其等效复阻抗等于()。
A.
B.
C.
D.
参考答案:A
Yesterday, when I went past the classroom, I _______ someone _______.
A.hear, singing
B.heard, singing
C.heard, sang
D.hear, sang
试述上下颌各牙齿及其牙龈和牙周膜的神经支配情况。