题目解析:
Franklin批评作为国家象征使用的动物为a rank coward,这里应该选择对此评价最恰当的反应。教授介绍这一点时,语气十分惊讶,再加上强调这一点确实在信中出现,可见教授认为这一评价十分尖锐。
【对应原文】
Franklin says a little more about how the bird is lousy and then adds, "Besides he is a rank coward." [Amazed] I'm not kidding-that's actually in the letter.