接种是组织培养过程中易于（）的一个环节，操作必须在无菌条件下进行。

A、褐化

B、玻璃化

C、成功

D、污染

The man, ______ is parked in front of our school, is a prominent policeman in this city.

A．whose red car

B．of whom the red car

C．of whose red car

D．the red car of his