安全阀能否正确安装，对阀门的工作状况、泄漏、排泄量等诸性能有极大的影响。
参考答案：对
We are so happy to see the problem _______ so quickly.
A．settled
B．having been settled
C．be settled
D．settling
肺源性心脏病时心影有时可呈
A．梨形心
B．横位心
C．靴形心
D．悬滴状心
E．主动脉型心脏
