What are the keywords in the following sentence? branch of russian birch with green leaves slow moving in the wind
birch, branch, wind

What are the keywords in the following sentence? this petite ring features a luminous pearl flanked by diamonds on a delicate gold band .
diamond, pearl, ring

What are the keywords in the following sentence? A train traveling through a forest with tall trees.
forest, travel, tree

What are the keywords in the following sentence? airplane moving on a runway
airplane, move, runway