Check these, please!

[Anonymous]

Hi,
Please check these sentences and correct them.
1. If you go away, I'll miss you in [half an hour, a half hour]. / Don't be so sad. I'll come back to you in two weeks.
2. It's the start of a new week/year!
3. I'm going to skip/fast breakfast this morning.
4. I had pretty good marks all through my school years/semesters/days.
5. You have a big spot on your neck. / [It's my birthmark.] or [It's one of my birthmarks.]
6. It is recommended to have a regular check-up every six months.
7. I don't mind taking a bus or a taxi.
Thanks a million.
Ann

[Rusty]

1. If you go away, I'll miss you in [half an hour, a half hour]. / Don't be so sad. I'll come back to you in two weeks. (OK).
2. It's the start of a new week/year! (OK).
3. I'm going to skip/ breakfast this morning.(Fast is an intransitive verb).
4. I had pretty good marks all through my school years/semesters/days. (OK).
5. You have a big spot on your neck. / [It's my birthmark.] or [It's one of my birthmarks.] (OK).
6. It is recommended to have a regular check-up every six months. (OK).
7. I don't mind taking a bus or a taxi. (OK).