C. keep each other company D. develop closer relations

29. The author mentions his experience in Thailand to show that________

A.. the English prefer to make long speeches

B. too many words are of no us

C. even talk and silence can be culturally different

D. people from Thailand are quiet and shy by nature

30.According to the text, how can people from different cultures understand each other better?

A. By recognizing different values B. By sharing different ways of life

C. By accepting different habits D. Bspeaking each other s language

31. What would be the best title for the text?

A. How to Understand Each Other B. Multicultural Ernvironment

C. How to Build Up a Relationship D. Cross-cultural Differences

　　Scientists are debating how to limit their newly-discovered power to change genetic

structure. Scientists already modify the genes of farm animals and agricultural plants to makethem more productive or stronger. But now they can also change genes in wild animals and plants. These genes would continue into later generations. For example, it may be possible for scientists to remove from existence the kind of mosquitoes that carry the Zika virus. Theymight also be able to permanently remove species of plants and animals that are destructive toother species.

　　In a report published last week, the U.S.National Academies of Sciences, Engineering and Medicine (NAS) said it supports continued research on this kind of gene control. But it warned that it is not possible to know what will happen when these changed plants and animals are released into the wild.

　　Sixteen biologists, ethicists(伦理学家) and policymakers are on an NAS committee that is examining the issue. They say that there is value to the new technology. But, they say, there is not enough evidence to support the release of modified organisms (生物体) from the laboratory into nature.

　　Many people would support stopping mosquitoes and rats from carrying diseases. But scientists say we must understand the possible scientific, ethical, legal and social results of such action before we decide whether to take it. Gene modification is spread through reproduction(繁殖).

　　Changed genes will continue to spread as long as an animal or plant continues to reproduce. They cannot be limited to a farm or kept within a country's borders. Scientists are wondering what may happen if a modified organism mates with another species. They are not yet sure how the modified genes would affect the other species. It is possible that those genes could harm those creatures or even lead to their disappearance from our planet.

32. What possible advantage does gene control in wild animals and plants have?

A. Changing the Zika virus permanently.

B. Removing the destructive species for ever.

C. Having changed genes in their next generations.

D. Making all the species more productive and stronger.

33. As for genetically changed wild animals and plants ,what are scientists worried about?

A. They may become weaker or die out.

B. They may be more productive.

C. They may cause damage to their living habitat.

D. Their genes may spread to later generations.

34. Which of the following is NOT true according to the passage?

A. Scientists are not sure what exact results gene modification leads to.