Bank of China informs the beneficiary, a Chinese import and export company that a foreign bank has opened a letter of credit in his favor. The bank does not add its engagement by informing the beneficiary. The Bank of China ia acting as （）.

A．The issusing bank 　　

B．The advising bank

C．The confirming bank 　　

D．The negotiating bank

贯注于心肺之脉的是什么气

A．元气
B．宗气
C．营气
D．卫气
E．后天精气