2013年职称英语考试《综合类B级》考试真题_职称英语考试真题综合类

2013年职称英语考试《综合类B级》考试真题

Sugar became a vital ingredient in all kinds of things, from confectionery (糖果点心) to medicine, and, as the demand for sugar grew, the industry became larger and more profitable.(47)Many crops withered (枯萎) and died, despite growers attempts to save them,and there were fears that the health of the plant would continue to deteriorate.

In the 1960s, scientists working in Barbodos looked for ways to make the commercial species stronger and more able to resist disease. They experimented with breeding programmes,mixing genes from the more delicate, commercial type.(48)This sugar cane is not yet ready to be sold commercially, but when this happens, it is expected to be incredible profitable for the industry.

(49)Brazil, which produces one quarter of the worlds sugar, has c~ordinated an international project under Professor Paulo Arrudo of the Universidade Estaudual de Campinas in Sao Paulo. Teams of experts have worked with him to discover more about which parts of the genetic structure of the plant are important for the production of sugar and its overall health.

Despite all the research, however, we still do not fully understand how the genes in sugar cane.(50)This gene is particularly exciting because it makes the plant resistant to rust,a disease which probably originated in India, but is now capable of infecting sugar cane across the world. Scientist believes they will eventually be able to gro.w a plant which cannot be destroyed by rust.