Correct the error in the sentence$\mathrm{.}17.$ The company sells bottles that they are made from recycled plastic$\mathrm{.}18.$ New York is one of the most expensive cities in a world$\mathrm{.}19.$ By the time she had been six years old, she had already started reading books$\mathrm{.}20.$ I like classical music. While my wife prefers jazz.