受体菌直接摄取游离的DNA而获得新的性状的过程称为（）。
A.转化
B.转导
C.接合
D.原生质体融合
E.溶原性转换
参考答案：A
— Bob, why do you stay silent? Can you tell me the answer?
— I'm sorry, Mr. Green. Your question is very difficult ________.[ ]
A. to be answered
B. to answer
C. answering
D. to have answered
