提示慢性肺心病右心室肥大的最主要表现是
A．心音低钝
B．心界缩小
C．P2=A2
D．剑突下有明显搏动
E．双肺听诊有湿啰音
参考答案：D
用树型结构表示实体类型及实体间联系的数据模型称为【 】
—What are you doing there?
—I am _______ my tennis racket. I can't _______ it. [ ]
A. looking at; find
B. working with; find
C. looking for; find
D. finding; find
