There is a tendency to utilize underground space for the less ornamental purposes of civilization; there is the Metropolitan Railway in London, for instance, there are new electric railways, there are subways, there are underground workrooms and restaurants, and they increase and multiply.
Polystyrene can be naturally transparent, but can be colored with colorants. Uses include protective packaging (such as packing peanuts and CD and DVD cases), containers (such as clamshells), lids, bottles, trays, tumblers, and disposable cutlery.
Polycarbonate plastic is used to make hard plastic items, such as baby bottles, re-useable water bottles, food containers, pitchers, tableware and other storage containers. You can also find polycarbonate plastic in eyeglass lenses, CDs, DVDs, computers, appliances, sports safety equipment and many other products.