下列哪种方法不能用于诊断冠心病（）。

A.负荷试验

B.超声心肌造影

C.彩色多普勒检查主动脉血流

D.检测心室收缩及舒张功能

Viruses can’t be transmitted by (74) and (75) is not a common route for virus infiltration.

A．booting a PC from an infected medium

B．accessing to ROM

C．opening an infected file

D．executing an infected program