In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

What has to be done with lights in order for them to work?, Context: Entry lights can be used outside to illuminate and signal the entrance to a property. These lights are installed for safety, security, and for decoration.
installed

What sounds like it should have vocal emphasis but does not?, Context: In some languages, such as English, aspiration is allophonic. Stops are distinguished primarily by voicing, and voiceless stops are sometimes aspirated, while voiced stops are usually unaspirated.
voiced stops

The name for an arithmetical value, expressed as a word or symbol used in counting and calculations is?, Context: Oklahoma City and the surrounding metropolitan area are home to a number of health care facilities and specialty hospitals. In Oklahoma City's MidTown district near downtown resides the state's oldest and largest single site hospital, St. Anthony Hospital and Physicians Medical Center.
number