please correct the grammar

Average bond distances in C-C (in an aromatic) and C=C (non-aromatic) in phenylpropene are the same average bond distances which have calculated in the exercise 1. Note that the bond distance in the exercise for C-C (in an aromatic) and C=C (non-aromatic) are 1.402 and 1.340 respectively. However, average bond distances in C-C (non- aromatic) is different from the first exercise (1.538 Å). This is due to the hybridisation of C(4), C(7) and C(8) are sp2.