在采用观察法收集资料的过程中，研究者参与被观察者的活动，但研究者主要角色仍是观察。此观察者的角色类型是（）
C
暂无解析
--Look! That man looks like Mr White.
--It _________ be him. Mr White _________America yesterday.
身份证明系统应该由几方构成?（）
—What's the weather going to be like at the weekend ?
— ______ .
______ progress you have make this term!
There are over six ________ students _____ part in the entrance exam in Dongcheng on May the second.
--Mike, you’ ve got so many beautiful stamps.
--Yeah. I _________ collect stamps when I was in primary school.
Pop music is _____ he likes most .
电子商务网站建设的核心是（）
《中华人民共和国对外贸易法》正式实施的时间是()。
—Would you mind my sitting here ?
— ______ .