在空里填一个宾语从句引导词

题目

在空里填一个宾语从句引导词
1.I have no idea _____ didn't come yesterday.
2.Do you know ____ I should give the letter to.
填适当的介词：
1.He said his father first made him think ___ music seriously.
2.On year later,she started collecting dolls _____ a hobby.
3.Tina showed great skill ____ the guitar.
4.Playing football is quite popular _____ the boys.
5.What can a successful hobby mean ____ a high school student?

答案

why
who
of
as
on
among
to