何时定语从句that不能替代who,which,whom.whose

1。限制性定语从句。就是前面有个","
for example:
The building,which was built in 1880 ,is the highest one in our school。
2。有介词
for example:
The students,most of which are under 18,are threntened by the addiction of the Internet。
3。who做连接词时,先行词为不定代词,如the one,somebody