A group of Asians are marching down a street while others look on.
Other people are watching the Asians.
The Asians are the only people outside.
A man in a hat is taking a nap under a tree.
I would collect them from the back, and move them to the front.
Guys in a boat.
A man is cooking dinner.
A boy is playing video games.
The change in air quality is never measured or estimated by anything.