ZAO Grow is a rapidly developing company that manufactures and retails sports and leisure goods. In order to achieve ts performance targets for the next two years, ZAO Grow has to raise new capital. ladimir is the general director of ZAO Grow. He has approached Loan Bank for funding. The bank will only provide oan facilities if ZAO Grow is prepared to grant a legal mortgage over its head office building, or alternatively if ladimir’s wealthy father will give a personal guarantee to underpin the lending contract.Required:

(a) Explain the nature of the two types of security sought by Loan Bank. (6 marks)

感染过程中最易识别的是（）

A．病原体被清除

B．隐性感染

C．潜伏性感染

D．病原体携带状态

E．显性感染