【题目】Despite barriers and hardships，they ______ the research on cloning tissues.
A. come up with B. catch up with
C. push ahead with D. put up with
在线课程【答案】C
【解析】考查动词词组。A. come up with跟上； B. catch up with赶上；C. push ahead with 推进； D. put up with忍受。句意：尽管遇到重重阻碍和困难，他们毅然进行克隆生物组织的研究。push ahead with毅然推进。根据句意可知选C。