Q: "A boy in a pink T-shirt is riding a bike over a sand pile while two others are riding in the street." Does this mean that "The boy is on a bike."?
A: yes

Q: "A grocery store clerk is checking out groceries being bought be a woman with an injured hand." Does this mean that "A man riding a bike."?
A: no

Q: "A person wearing a hat and glasses sits on a cliff and smiles." Does this mean that "The person has glasses on their face."?
A: yes

Q: "A black and white dog jumps over a hurdle." Does this mean that "A dog leaps over an obstacle"?
A:
yes