What is the preposition in the following sentence?

as derek washed the windows, jill worked beside him.

a.
worked

b.
as

c.
him

d.
beside

the anwser is went creeping down the river again, across the wide lonely marshes to the sea.

i longed to go with them out into the world to seek my fortune in foreign lands—africa, india, china and peru!

and, dreaming of the lands i had never seen, i'd sit on there, watching till they were out of sight.

sugar had three primary uses in ancient india. it was used in religious rituals, consumed as a snack, and considered a type of medicine.

black citizens were denied access to the same public facilities as whitesun.

marriages between white and nonwhite citizens were forbidden.

nonwhite citizens were required to carry identification papers with them at all times.