膜部和肌部室间隔缺损，有自然闭合的可能，一般在()
A．七岁以内
B．五岁以内
C．三岁以内
D．两岁以内
E．一岁以内
参考答案：B
扬声器俗称喇叭，用英文表示为Loudspeaker。( )
______ he was exercising at the park yesterday morning, he found a purse under the tree.
A. While B. Before C. Though
