Q: "Onlookers watch as a parade goes by with soldiers." Does this mean that "The onlookers are lined up on a sidewalk."?
A: it is not possible to tell

Q: "People roaming the street." Does this mean that "No one could be seen on the street."?
A: no

Q: "A black dog is swimming while carrying a tennis" Does this mean that "a dog is on dry land."?
A: no

Q: "Two children are sitting side by side and looking at books." Does this mean that "Two children are sitting and looking at books."?
A:
yes