Hopatcong resident Susan Slinger spent years as a South Plainfield Middle School physical education teacher. But it wasn't all push-ups and kickball.

Slinger, now retired, also had to teach health class. And as part of the five-week session, two weeks were focused on sexual education.

In her new book, "Can a Sperm Swim Backwards?," Slinger answers real sex-ed questions from students. Slinger solicited the questions by placing a "question box" on her desk, allowing students to submit their queries anonymously

"In our day," Slinger said in a press release, "parents didn’t talk about sex. We learned it from books hidden under our bed or in our friend’s tree house, from wild stories our friends shared with us, and other uninformed and often humorous sources."

Slinger, who also lives in Boca Raton, Fla., is a grandmother. She volunteers at the Lynn Cancer Center in Florida.

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