12岁，男孩，肺动脉瓣区第2音增强，胸骨左缘第3肋间有3级收缩期杂音，心尖附近有短促舒张期杂音，平日偶有膝关节疼痛，无发绀史。心电图：电轴＝＋120°，RV1＋ SV5＝1.2mV，X线检查右心室大。应首先考虑
A．室间隔缺损
B．房间隔缺损
C．动脉导管未闭
D．风湿性心脏病
E．法洛四联症
参考答案：B
解析：根据杂音特点、心电图(电轴右偏)、X线(右室大)等，可疑诊断房缺。
| 32．Communicating via E-mail is by far the most common Internet activity. You can (1) with anyone in the world who has an Internet address or E-mail (2) with a system connection to the Internet. All you need is (3) the Internet and an E-mail program Two of the most widely used E-mail programs are Microsoft’s (4) and Netscape’s Navigator. A typical E-mail message has three basic (5) ：header, message, and signature. |
(2)
A．full
B．lost
C．inundated
D．filled