What are the keywords in the following sentence? ship coming in from an island crossing to a port
come, port, ship

What are the keywords in the following sentence? A train moving along some train tracks next to a tree.
move, train, tree

What are the keywords in the following sentence? politician with the first train to carry the new livery at station .
carry, politician, train

What are the keywords in the following sentence? a construction site where a shopping centre will be built just outside structure .
build, centre, site