下列局麻药中哪种比普鲁卡因代谢快()
A．布比卡因
B．氯普鲁卡因
C．利多卡因
D．丁卡因
E．罗哌卡因
参考答案：B
When we practice speaking English, we often end up _______ in Chinese.
A．to speak
B．speak
C．spoken
D．speaking
何谓“四元”？
