发酵生产中常用菌种的保藏方法有（）.
A.冷冻保藏
B.冻干保藏
C.传代保藏
D.矿物油中浸没保藏
参考答案：A, B, C, D
Though I really enjoyed the Guangzhou 2010 Asian Games, I found it rather difficult to understand the local people because of their confusing ____.
A．remark
B．accent
C．slogan
D．motto
