Question

Special trees that grow faster, fight pollution, produce better wood, and even sense chemical attacks are being planted by scientists in the US．

              When 40 per cent of Hawaii's US$14 million-a-year papaya （木瓜）industry was destroyed by a virus five years ago, work began on creating genetically engineered（转基因的）trees．

              Researchers successfully introduced seeds that were designed to resist the virus．Since then, more and more people have been testing genetically engineered trees．Some researchers put special bacteria into trees to help them grow faster and produce better wood．Others are trying to create trees that can clean polluted soil．Meanwhile fruit farmers are looking for trees that are strong enough to resist worms, and paper companies want trees that produce more wood and therefore more paper．

              The Pentagon （五角大楼） even gave the researchers US$500,000 this year after they developed a pine tree that changes its colours if it senses a chemical attack．So far, the poplar, eucalyptus （杨树与桉树）, apple and coffee trees are among those being engineered．All this can be done today because we have a better understanding of tree genomes （基因组）．

              However, some people fear that the genetically engineered trees will cause dangerous results．They are worried that the new trees will breed with natural species and change the balance of the forest environment．

              “It could be destructive,” said Jim Diamond, an environmentalist. “Trees are what is left of our natural environment and home to many endangered species.”

              But researchers insist that science could give nature a fighting chance against both natural and man-made dangers．They hope to answer the critics by stopping the new trees from breeding, so their effect on the environment can be controlled．

1.Which kind of tree is not the ones that scientists are planting in the US?

A．Trees that worms can't hurt．

B．Genetically engineered trees．

C．Trees that can resist wind better．

D．Trees that can protect themselves at a chemical attack．

2.What caused the American scientists to work on special trees?

A．Tree genomes are mapped out so scientists know how to improve trees．

B．Great numbers of trees have been lost due to attacks by viruses．

C．Researchers successfully introduced seeds designed to resist the virus．

D．They think science could give nature a fighting chance against both natural and man-made dangers．

3.Which of the following was probably the first kind of trees being engineered?

A．Papaya．                                          B．Pine．                                          C．Apple．                                          D．Poplar．

4.Why did critics think engineered trees dangerous? Because ________．

A．these trees can destroy the balance of nature

B．everything except trees has been genetically engineered

C．trees are home to many endangered species

D．these trees may affect normal trees

Answer

1.C

2.B

3.A

4.D

【解析】

试题分析：美国科学家最近研制出了一些特殊树种，这些树可以抗污染、出产更多的木材、能够察觉到化学物质的侵害。但是有些人害怕这种转基因的树种会与原先的自然树种进行杂交，从而威胁到自然物种，最终造成森林环境的破坏。

1.C细节理解题。通过文章第三段Meanwhile fruit farmers are looking for trees that are strong enough to resist worms；第四段中they developed a pine tree that changes its colours if it senses a chemical attack和So far, the poplar, eucalyptus, apple and coffee trees are among those being engineered．可以判断只有C选项中抗风的树木没有在美国种植，故答案选C。

2.B细节理解题。根据文章第二段内容When 40 per cent of Hawaii's US$14 million-a-year papaya industry was destroyed by a virus five years ago, work began on creating genetically engineered trees．可以判断是由于木瓜产业受到了病毒的危害，研究人员才开始了转基因树种的研究工作，故答案选B。

3.A细节理解题。从文章第二段内容可知自从五年前木瓜产业受到病毒危害后，研究转基因树种的工作就开始了，由此判断木瓜是首先被研究的转基因树种，答案选A。

4.D 细节理解题。根据文章倒数后三段段内容They are worried that the new trees will breed with natural species and change the balance of the forest environment．可知人们反对种植这种树的原因是害怕这些树会和普通树木杂交从而会影响森林环境，故答案选D。

考点：考查社会科学类短文阅读。