it is subject because teacher is a subject
1 - he
2 - her
3 - him
4 - me
5 - his
6 - he
7 - she
8 - it
9 - his
10 - me
11 - you
12 - I
13 - her
14 - I
15 - you
(this is assuming Tom is male)
What has to happen to the plates for an earthquake to occur? the tectonic plates would have to shift. They slide past one another.