All the students from our class went on the excursion to Turkey except for Lily. My son always finds it difficult to understand his lessons in Physics and History

1.All the students from our class went on the excursion to Turkey except for Lily.
-> Lily was ............
2.My son always finds it difficult to understand his lessons in Physics and History.
-> My son always has ........................
3.Someone will tell him that news .
-> He ................
-> That.................
4.All my colleages read online newspapers as soon as they arrive at the office.
-> On ................
5.I don't have the slightest idea why Erika and her husband left the party that early.
-> I have no idea what...................