A. frustrated B. encouraged C. puzzled D. endangered 参考答案:A 答案解析:[参考译文] 他的试验失败了一次又一次,但他一点也不灰心。 [试题分析] 本题是一道词义辨析题。 [详细解答] frustrate”含义为“挫败,使感到灰心”;“encourage”含义为
第32题: [简答题]Question: Summarize the lecture and explain how maternal care affects the behavior of adult rats. 参考答案: 答案解析:The lecture talks about how maternal care affects the development of offspring and the speaker uses