单项选择题 Although scientists have______long the human appendix as______organ, there is a growing body of evidence indicating that the appendix does in fact have a significant function as a part of the body's immune system.（）

单项选择题 The primary impulse of each human being is to______himself, but the secondary impulse is to venture out of the self, to correct its provincialism and heal its loneliness.（）

单项选择题 Even if the public ate up every______detail about their leaders, that same public grew offended that the news media would actually pander to their baser impulses.（）