sentence 1: How do I know if I'm good?
 sentence 2: How do I know what I'm good at? sentence 1: How is it that a heavy train can float on superconductive tracks? How much power is required per ton of weight?
 sentence 2: How do magnetic levitation trains work? sentence 1: What is the difference between an infant, a baby, a kid and a child?
 sentence 2: Do babies also feel the pain of child birth?
not same meaning
not same meaning
not same meaning