Many researchers are currently trying to____. A.use animals involved in research more effectively B.slow down the transition for some experiments C.challenge the scientific value of animal testing D.raise the cost of using any animals in research
A.A.use B.slow C.challenge D.raise
【参考答案】
A 解析：题目问：很多研究者正试图干什么?通过阅读文章可知，由于不同的物种对相同的程序会有不同的反应，所以，一些......