单项选择题 当客人烟缸内有（）个烟蒂时，须为客人更换烟缸

单项选择题 在校期间,主修课程取得85分,相应得到的基点为( )。

未知题型 Judge whether the following statements about discussion are true or false. 1. Discussion is a process of interactive communication of reasons concerning a debatable issue.