She thought his smug two-year-old grin of self-amusement and satisfaction would drive her to the brink, but she maintained her composure.

In short, the Sun's large-scale magnetic field is taken to be self-sustaining, so that the solar-activity cycle it drives would be maintained with little overall change for perhaps billions of years.

Phone can be only installed and maintained by professionals. self install and maintain may cause danger, and against guarantee regulations.