What are the keywords in the following sentence? Two transit trains are pulled up at a station with passengers walking alongside.
pull, station, train, walk

What are the keywords in the following sentence? american football player warms up during mini camp
camp, player, warm

What are the keywords in the following sentence? A clock mounted on the side of a yellow wall.
clock, mount, wall

What are the keywords in the following sentence? A grandfather teaches his grandson to fish.
fish, grandfather, grandson, teach