What are the keywords in the following sentence? maple leaf the symbol on the forest floor in autumn an urban wilderness
autumn, floor, wilderness

What are the keywords in the following sentence? boats travel under the many bridges
boat, bridge, travel

What are the keywords in the following sentence? A white train at a docking station that is surrounded by gates and gravel.
gravel, station, train

What are the keywords in the following sentence? bull elk with antlers in velvet during the summer
antler, summer, velvet