Active noise-cancellation systems require______.
A. microphones
B. microprocessors
C. loudspeakers
D. all of the above
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As did his______ Sigmund Freud, Albert Einstein, and Henry Ford, Thomas Edison profoundly
A. contemporaries
B. part-owners
C. companions
D. accomplices
What office furniture do they need？
A. filing cabinets
B. desks
C. executive chairs
From the passage we know______.
A. fire made human beings free from bacterial and parasitic infestation
B. fire enabled human beings to deal with immediate emergencies more efficiently
C. fire made some animals frightened
D. fire helped human beings change their eating habits completely
What discount is offered？
A. 8%
B. 10%
C. 12%
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