基因治疗最理想的选择（）

A.基因封闭

B.基因替代

C.基因校正或置换

D.“自杀基因”疗法

E.非病毒载体介导法

What does salt water draft mean?（）.

A.It means summer draft

B.It means maximum draft

C.It means fresh water draft

D.It means seawater draft