Translate the following into Chinese One of the reasons that synthetic polymers (including rubber) are so popular as engineering materials lies with their chemical and biological inertness. On the down side, this characteristic is really a liability when it comes to waste disposal. Polymers are not biodegradable, and, as such, they constitute a significant land-fill component; major sources of waste are from packaging, junk automobiles and domestic durables. Biodegradable polymers have been synthesized, but they are relatively expensive to produce. On the other hand, since some polymers are combustible and do not yield appreciable toxic or polluting emissions, they may be disposed of by incineration.