Bakshi $8\mathrm{.}9$: Answer the following questions for assessing a polyethyl terepthalate $($PET$)$ bottle.

a$.$ Identify processes in the life cycle of this plastic bottle that may be most important. Draw the corresponding process network and show the important inputs and outputs for each process in your network.

b$.$ Identify economic sectors that provide inputs to the process network developed in the previous question and develop a hybrid network model for a PET bottle. You may use the North American Industrial Classication System for determining appropriate economic sectors$.$