【分析解答题】

They have selled their products in 20 countries. ... ...sold ... ..

British farmers are troubled by straw. They produce more than
41. ten millions tons every year as a byproduct of farming and
42. their animals need only four million tons for bedding and fooding.
43. Since European air-pollution laws forbid people to burnt straw,
44. the extra straw is plowed under or leave to rot. Scientists have
45. now found a way to put the straw to good using by changing a
neat-loving bacterium in the straw.