operate vs remain

operate

verb
  • To put into, or to continue in, operation or activity; to work. 

  • To deal in stocks or any commodity with a view to speculative profits. 

  • To perform some manual act upon a human body in a methodical manner, and usually with instruments, with a view to restore soundness or health, as in amputation, lithotomy, etc. 

  • To act or produce effect on the mind; to exert moral power or influence. 

  • To perform a work or labour; to exert power or strength, physical or mechanical; to act. 

  • To produce, as an effect; to cause. 

  • To produce an appropriate physical effect; to issue in the result designed by nature; especially (medicine) to take appropriate effect on the human system. 

remain

verb
  • To continue in a state of being. 

  • To await; to be left to. 

  • To continue unchanged in place, form, or condition, or undiminished in quantity; to abide; to stay; to endure; to last. 

  • To be left after a number or quantity has been subtracted or cut off; to be left as not included or comprised. 

  • To stay after others or other parts have been removed or otherwise disappeared. 

noun
  • That which is left; relic; remainder. 

  • That which is left of a human being after the life is gone; relics; a dead body. 

  • Posthumous works or productions, especially literary works. 

How often have the words operate and remain occurred in a corpus of books? (source: Google Ngram Viewer )