$14\mathrm{.}9$Refer again to Problems $14\mathrm{.}5$ and $14\mathrm{.}7.$ In addition to $100$ units of S$,$ there is also a demand for $20$ units of U$,$ which is a component of S$.$ The $20$ units of U are needed for maintenance purposes. These units are needed in week $6.$ Additionally, a new order has been received for $80$ units of S due in week $8.$ Modify the net requirements plan to reflect these changes. $[$PX$]$