1.There are 100people involved in this survey, the majority of _whom____said that they joined T
online groups in an effort to volunteer at the disaster site.
此题the majority of _whom____said that they joined...site.是一个非限制性定语从句,whom用来指代前句中的100people.
2.The video,__in which___ he shows no sign of self-pity ,has now been viewed more than 10000views.
此题中_in which___ he shows no sign of self-pity 是非限制性定语从句,in which=in the video(在这段录像里他丝毫没有自责的迹象）
3.__Apart from ____a few faults,she is one of the most excellent students in her school,___which____is known to every student.
Apart from 可以=besides,或except,第一个空,还可以用except. __which____is known to every student.这部分是非限制性定语从句,其中which 指代前面整个句子,而不是指人.
提示：你的定语从句部分学的不太好,可以把这部分重点复习下,如果你是大学生的你话,可以购买汪家杨、李俊峰编写的《大学英语语法》,此书非常实用,我给我的学生多次推荐过,祝每天进步一点点.