转导
参考答案：是指以噬菌体为媒介，将细菌的小片段染色体或基因从一个细菌转移到另一个细菌的过程。
Mr. Ken _______ more than sixty Chinese paintings since he came to Shanghai five years ago. [ ]
A. collects
B. collected
C. has collected
D. will collect
如果用交流电压表测量某交流电压，其读数为380伏，此交流电压的最大值为（）伏。
