there is _______ that cloning is ____ in some fields A.no doubt helpful B.not doubt useless

问题描述:

there is _______ that cloning is ____ in some fields A.no doubt helpful B.not doubt useless
C.some doubtuse
D.any doubt

A 此句子意思为:毫无疑问,克隆对一些领域是有帮助的.