Choose the word (A, B, C, or D) that best fits each blank space in the following passage. Over the last few years, “green” consumers (30) ______ widely used biodegradable plastic bags instead of traditional ones in (31) ______ to deal with the problem of white pollution. Does this craze really cause (32) ______ harm to the environment? Unfortunately, this is not always the case. It is because these bags, although made from (33) ______ plastics, can easily be degraded only when temperature, ...

Choose the word (A, B, C, or D) that best fits each blank space in the following passage.

Over the last few years, “green” consumers (30) ______ widely used biodegradable plastic bags instead of traditional ones in (31) ______ to deal with the problem of white pollution. Does this craze really cause (32) ______ harm to the environment? Unfortunately, this is not always the case. It is because these bags, although made from (33) ______ plastics, can easily be degraded only when temperature, humidity and soil quality reach certain levels. (34) ______, this condition can be controlled just in the laboratory, not always in reality.