左心房平面相当于
A．第3胸椎平面B．第4胸椎平面C．第5胸椎平面D．第6胸椎平面E．第7胸椎平面
参考答案：E
.
On hearing the _________ voice, the little girl became _________.
A．terrifying; terrifying
B．terrifying; terrified
C．terrified; terrified
D．terrified; terrifying
潜在的帕累托改进
