Children's school scissors are made from 4 items: two identical blades, a screw, and a nut. The blades are manufactured internally with a two-week lead time. The screw and nut are purchased from a hardware supplier with one-week lead time. The assembly process for one gross of scissors (10 dozen) is a week. Construct a product tree, and an MRP table. Assuming there are orders of one gross in week 7, 3 grosses in week 9 . There are 360 blades, 500 screws and 100 nuts currently available in inventory. Assuming the lot-of-lot policy is used