What are the keywords in the following sentence? earth rotates in a dark space
earth, rotate, space

What are the keywords in the following sentence? romanesque revival structure as seen from a stop on the tour
stop, structure, tour

What are the keywords in the following sentence? infections happen while patients are in hospitals each year .
happen, hospital, patient

What are the keywords in the following sentence? a religious mural adorns the wall of a church the oldest town
adorn, mural, wall