Tell whether the words printed in italics in the following sentences,
are prepositions or adverbs and the reason why:
1. He came _across_ the street.
2. He is _without_ work.
3. Come _in_.
4. He lives _near_.
5. He brought it _for_ me.
6. I cannot get _across_.
7. We will go _outside_.
8. This is _between_ you and me.
9. He can go _without_.
10. Stay _in_ the house.
11. Do not come _near_ me.
12. They all went _aboard_ at six o'clock.
13. He enlisted _in_ the navy and sailed _before_ the mast.
14. I do not know what lies _beyond_.
15. I will soon be _through_.
16. The aeroplane flew _above_ the city for hours.