sentences:  As expected, graphene nanoribbons with smaller width would completely break down faster, since the ratio of the weaker edged bonds increased.While the tensile strain on graphene nanoribbons reached its maximum, C-C bonds would start to break and then formed much bigger rings to make materials weaker until fracture.The earliest numerical results on the optical properties of graphene nanoribbons were obtained by Lin and Shyu in 2000.