問題詳情

C.
      A team of researchers at the Helmholtz Center for Environmental Research in Leipzig, Germany, has found that a strain of soilbacterium, identified as Pseudomonas putida, can produce enzymes to digest polyurethanes, thus making ____26____biodegradable. The study offers hope of ridding the planet ____27____ the growing quantities of discarded plastic products thatthreaten human and animal life. But some scientists are skeptical. In earlier experiments, biodegradation of some plasticcomponents was achieved with fungi. Yale University students in 2011 discovered a fungus that can digest and break downpolyurethane plastic even in a place without air. Since then scientists around the world have identified other fungal species thatcan break down polyurethane.
      Despite new findings, science is nowhere near solving the growing plastic pollution problem. Humankind has manufacturedand discarded so much plastic over the years that the world is ____28____ places to dump the enormous quantities accumulatedevery day. Refusal by many developing countries to accept plastic waste from rich nations has exacerbated the problem.
      Some countries are cutting down on the use of plastic bags, drinking straws, plastic bottles and utensils. Scientists keep comingup with new biodegradable products to replace plastic, such as wrapping materials made from algae, straws made of paper anddisposable utensils made of bamboo, but the movement could be described as “too little, too late.” Recycling the plastics to makebuilding materials, fabrics, and ____29____ new plastic products cannot even make a dent in the growing amounts of plastic waste.Plastic remains the most practical packaging material and is indispensable in medical, pharmaceutical, sanitary and many industries.Some new biodegradable, but equally useful material, has yet to be developed. ____30____ scientists estimate that about 8 millionpieces of plastic enter the oceans every day. For some of them it will take hundreds of years to properly degrade if they are notfirst swallowed by fish and other marine creatures that will die from it.
26.
(A) that
(B) this
(C) what
(D) it

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