女性，15岁。2周前咽痛、流涕、咳嗽，按感冒治疗好转。近1周来心悸、胸闷、气急，两天来夜间不能平卧，并且反复出现黑朦入院诊治。心电图示：第三度房室传导阻滞。

入院查体：BP100／60mmHg，HR40次／分，心脏扩大，心尖部闻及S3奔马律，双肺底闻及湿啰音。考虑反复发生黑朦的原因是（）

A.心力衰竭

B.心源性休克

C.第三度房室传导阻滞

D.中枢神经系统感染

E.脑栓塞

Microsoft’s COM is a software architecture that allows applications to be built from binary software components. COM is the underlying (48) that forms the foundation for higher-level software services, like those provided by OLE. COM defines a binary standard for function calling between components, a way for components to dynamically discover the interfaces implemented by other components, and a mechanism to identify components and their interfaces uniquely.

OLE is a compound (49) standard developed by Microsoft. OLE makes it possible to create (50) with one application and link or embed them in a second application. Embedded objects retain their original format and (51) to the application that created them. Support for OLE is built into the Windows and MacOS Operating Systems. A (52) compound document standard developed mainly by Apple and IBM is called OpenDoc.

50（）

A.event 

B.table 

C.function 

D.objects