Which of the following is not true about minerals?
They always include oxygen and silicon.
They are naturally occurring materials.
They each have unique properties.
They have a crystalline structure.

What types of jobs typically are found in ghetto, inner-city neighborhoods? a. low-wage positions, typically in retail outlets, that require little education b. professional positions with banks, doctors' offices, and other similar businesses c. hourly factory and manufacturing positions d. positions that require advanced education, such as those in financial or technology firms select the best answer from the choices provided.