The following text is for questions 17 to 20.

    Ruth Handler, famously known for the invention of the iconic Barbie doll, was once president of the Mattel Inc. toy manufacturing company. She was born in Denver, Colorado in 1916.

    Ruth moved to Los Angeles, California in 1938 with her husband Elliot Handler. Mattel Inc. was created by Ruth's husband Elliot Handler and his partner Harold Matson in 1945. What began as a picture frame manufacturing company slowly transformed into a toy company when its creators began crafting dollhouses out of wooden scraps.

    Barbara Handler, Ruth's daughter, was fond of paper dolls as a child. She would play with them as if they were grown ups, rather than children her own age. Being an attentive mother, Ruth soon realized that children frequently preferred to be adults when playing. She declared that children are more interested in their futures than the present moment.

    This gave Ruth the idea to craft an adult doll that was not paper, like all the others, but three dimensional. The fully formed plastic doll could wear clothing made from real fabric, rather than the ill-fitting paper clothing used for traditional dolls. In 1959, Ruth revealed her new doll at the New York toy fair. It was named Barbie, after her daughter.

    Ruth Handler died in 2002, at the age of 85, due to a complication during surgery to treat colon cancer, but her legacy has lived on. The Barbie doll is still one of the most famous and profitable toys for young girls in America and around the world.

Adopted from: http://www.wepanknowledgecenter.org/ruthhandler/ (September 23, 2019)

"She would play with them as if they were grown ups, ...." (Paragraph 3)
The underlined word refers to ____.