室间隔缺损的血流动力学改变首先引起（）
A.右室增大
B.左房增大
C.主动脉扩张
D.肺动脉扩张
E.以上都不是
参考答案：A
_____. Is this your pencil case? [ ]
A. Hello
B. I'm sorry
C. Excuse me
----I _____this morning, but he could not come.
----Well, we’d better go and _____at his office.
A．called him; call on him
B．called on him; call him
C．called at him; call
D．called him; call at him
