新概念三第一课课文第二句为什么是同位语从句?从那看出来的?
when reports came into london zoo that a wild puma had been spotted forty-five miles south of london,they were not taken seriously.为什么是同位语从句而不是定语从句?不懂啊
还有，怎么能看出that是否充当了成分呢？是不是看that去掉了整句话的句子就读不通了呢？