第4部分:阅读理解
下面有3篇短文,每篇短文后有5道题。请根据短文内容,为每题确定1个最佳选项。
Salty Rice Plant Boosts Harvests
British scientists are breeding a new generation of rice plants that will be able to grow in soil containing salt water. Their work may enable abandoned farms to become productive once more.
Tim Flowers and Tony Yeo, from Sussex Universitys School of Biological Sciences, have spent several years researching how crops, such as rice, could be made to grow in water that has become salty.
The pair have recently begun a three-year program, funded by the Biotechnology and Biological Sciences Research Council, to establish which genes enable some plants to survive salty conditions. The aim is to breed this capability into crops, starting with rice.
It is estimated that each year more than 10m hectares (公顷) of agricultural land are lost because salt gets into the soil and stunts (妨碍生长) plants. The problem is caused by several factors. In the tropics, mangroves (红树林) that create swamps (沼泽) and traditionally formed barriers to sea water have been cut down. In the Mediterranean, a series of droughts have caused the water table to drop, allowing sea water to seep (渗透) in. In Latin America, irrigation often causes problems when water is evaporated (蒸发) by the heat, leaving salt deposits behind.
Excess salt then enters the plants and prevents them functioning normally. Heavy concentrations of minerals in the plants stop them drawing up the water they need to survive.
To overcome these problems, Flowers and Yeo decided to breed rice plants that take in very little salt and store what they do absorb in cells that do not affect the plants growth. They have started to breed these characteristics into a new rice crop, but it will take about eight harvests before the resulting seeds are ready to be considered for commercial use.
Once the characteristics for surviving salty soil are known, Flowers and Yeo will try to breed the appropriate genes into all manners of crops and plants. Land that has been abandoned to nature will then be able to bloom again, providing much needed food in the poorer countries of the world.
1 Which of the following statements about Flowers and Yeo is true?
A They are students at Sussex University.
B They are rice breeders.
C They are husband and wife.
D They are colleagues at an institution of higher learning.
2 Flowers and Yeo have started a programme
A to find ways to prevent water pollution.
B to identify genes that promote growth in salty soil.
C to breed rice plants that taste salty.
D to find ways to remove excessive salt from soil.
3 Which of the following is NOT mentioned as a cause of the problem discussed in the passage?
A Natural barriers to sea water have been destroyed.
B The water table has gone down after droughts.
C Sea level has been continuously rising.
D Evaporation of water leaves salt behind.
4 The word affect in Paragraph 6 could be best replaced by
A influence.
B effect.
C stop.
D present.
5 The attitude of the author towards the research project is
A positive.
B negative.
C suspicious.
D indifferent.
答案:1. D 2. B 3. C 4. A 5. A
体坛英语资讯:Stosur beats Serena to lift first major trophy at US Open
体坛英语资讯:Haedo wins confusing sprint in stage 16 of Vuelta
体坛英语资讯:U.S. captain cited for dangerous play during Rugby World Cup
体坛英语资讯:Mourinho wants concentration against Levante
体坛英语资讯:Nadal suffers collapsing cramp in news conference
体坛英语资讯:All matches on Wednesday canceled due to rain at US Open
体坛英语资讯:Wozniacki sets up semifinal against Serena, Zvonareva falls out
体坛英语资讯:Euro 2017 main stadium to open on Oct. 8
体坛英语资讯:Azerbaijan, Iran and Bulgaria win golds on 1st day of wrestling worlds
体坛英语资讯:France wins doubles to remain alive in Davis Cup quarter-final
体坛英语资讯:Bolt beats Zagreb track record in mens 100m
体坛英语资讯:Djokovic wins marathon tiebreak to reach US Open quarters
体坛英语资讯:US Open wraps up late for fourth straight year
体坛英语资讯:Tsonga rallies past Fish to make US Open quarters
体坛英语资讯:Top four men into US Open last four
体坛英语资讯:China still alive, World Champions unstoppable
体坛英语资讯:American duo Huber/Raymond win US Open womens doubles
体坛英语资讯:Real Sociedad fight back to deny Barcelona
体坛英语资讯:Brazil to offer mobile broadband internet for 2017 World Cup
体坛英语资讯:Argentinas River supporters sentenced to life in prison
体坛英语资讯:Brazil beat Portugal to reach beach soccer World Cup final
体坛英语资讯:S. African womens soccer team qualifies for London Olympics
体坛英语资讯:Ibra ruled out of Barcelona clash
体坛英语资讯:Chinese Taipei secures second round berth at Asian Championship
体坛英语资讯:Bolt marks season best at Brussels Diamond League
体坛英语资讯:Fred complains of pain, doubtful for national soccer team
体坛英语资讯:Coritiba creams Botafogo 5-0, Flamengo keeps winless
体坛英语资讯:Djokovic into semis, Nadal, Murray, Roddick reach US Open quarters
体坛英语资讯:Ronaldo happy to end career at Real Madrid
体坛英语资讯:Chiles run for 2017 World Cup in jeopardy after injury