缩窄性心包炎病因最常见的是（）
A.化脓性感染
B.外伤性血心包
C.风湿性心包炎
D.结核性心包炎
E.肿瘤性心包炎
参考答案：D
The couples went into the forest,but before long they became _________;they walked down different paths.
A．lost
B．missing
C．separated
D．reunited
=（）。
A．0
B．1
C．e2
D．e3
=（）。