When a bridge transmits an Ethernet frame, the Ethernet frame has （）.

A.the broadcast address for the its source address

B.the bridge's LAN address for its destination address

C.the bridge's LAN address for its source address

D.none of the above

患者，女，28岁，右下第三磨牙阻生反复肿痛，需拔除。患者自诉害怕打针，曾有晕针史。术前已进食，休息可。治疗设计为局麻下拔除，十分钟后试麻效良好，医生开始操作，术中患者头晕、胸闷、面色苍白、全身冷汗、四肢厥冷无力、脉搏快而弱、恶心、呼吸困难。

最可能引起上述症状的原因是（）

A.恐惧

B.饥饿

C.疲劳

D.疼痛

E.全身健康较差