In many countries, some scientists are already research in order to produce a cloned human baby.
A. putting up with
B. ing up with
C. putting forward
D. pushing ahead with
网友回答
A. putting up with
B. ing up with
C. putting forward
(答案→)D. pushing ahead with
解析：考查短语辨析。A忍受；B提出，想出；C提出；D推动；句意：在很多国家里，为了生产克隆婴儿，一些科学家已经在推进研究工作了。根据句意说明D正确。