I recommend two science fiction novels suitable for 14 to 18-year-olds with deep thinking value: 1. " Bird's Strings ": This is a science fiction novel written by the author, Old Ghost Shifang. Although the plot is bizarre, it exudes subtle human concern. Through the adventures of the protagonist, Bird Silk, the readers could think about the relationship between humans, between humans and nature, and between humans and technology. 2. " The Age of the System's Superpowers " was an urban science fiction novel by the author, the transparent carrot. It was a work with strong human concern. Through the experience of the protagonist, Tang Yong, the readers can deeply feel the fragility of human nature, as well as the dilemma of human survival when technology and superpowers meet. I hope you like the above recommendations.