1 . Directions: Fill in each blank with a proper word chosen from the box. Each word can only be used once. Note that there is one word more than you need.

A. directly	B. conventional	C. sorted	D. sustainable	E. landfilling	F. supply
G. dating	H. undoubtedly	I. viewed	J. packaging	K. cardboard

Recycling can be defined as the process of converting waste materials into new materials and objects. It can save material and help lower greenhouse gas emissions. The aim of recycling is to avoid     1     waste disposal. It contributes to the prevention of the waste of potentially useful materials and reduces the consumption of fresh raw materials, thereby reducing: energy usage, air pollution, and water pollution from     2    . This practice has been around throughout the history of mankind,     3     from the fourth century BC.

Recyclable materials include many kinds of glass, paper, and     4     metal, plastic, tires, and electronics. The composting(堆肥) or other reuse of biodegradable waste- such as food or garden waste- is also     5     as recycling.

Materials to be recycled are either brought to a collection center or picked up from the roadside, then     6     cleaned, and reprocessed into new materials for manufacturing.

In the strictest sense, recycling of a material would produce a fresh     7     of the same material- -for example, used office paper would be changed into new office paper. However, this is often     8     difficult or too expensive (compared with producing the same product from raw materials or other sources), so “recycling” of many products or materials involves their reuse in producing different materials instead. Another form of recycling is the rescue of certain materials from complex products, either due to their intrinsic（内在的） value or due to their dangerous nature.

Much of the difficulty in recycling comes from the fact that most products are not designed with recycling in mind. The concept of     9     design aims to solve this problem. Now scientists suggest that every product and all     10     they require should have a complete “closed-loop” cycle mapped out for each component- a way in which every component will either return to the natural ecosystem through biodegradation or be recycled indefinitely.