What are the keywords in the following sentence? punching hand with a clenched fist aimed directly at the viewer isolated on grey
clench, hand, isolate, punch, viewer

What are the keywords in the following sentence? isotopes all atoms of element have the same number of protons .
atom, element, isotope, number, proton

What are the keywords in the following sentence? village from the pier with some boats
boat, pier, village

What are the keywords in the following sentence? satellite captured this ultraviolet image of the moon eclipsing the sun .
capture, moon, satellite, sun