题目内容
【题目】七选五
根据短文内容,从短文后的七个选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。
It is said that farmers or peasants, especially those in developing countries, are often criticized for cutting down forests. But a new study suggests that many farmers recognize the value of keeping trees.
Researchers using satellite images found at least ten percent trees cover on more than one billion hectares of farmland. 1 . Earlier estimates were much lower but incomplete. The authors of the new study say it may still underestimate the true extent worldwide.
The study found the most trees cover in South America. 2 . North Africa and West Asia have the least.
The study found that climate conditions alone could not explain the amount of trees cover in different areas. 3 . There are areas with few trees but also few people, and areas with many trees and many people. The findings suggest that things like land rights, markets or government policies can influence tree planting and protection.
Dennis Garrity heads the World Agroforestry Center. 4 . The problem, he says, is that policy makers and planners have been slow to recognize this and to support such efforts.
The satellite images may not show what the farmers are using the trees for, but trees provide nuts, fruit, wood and other products. 5 . Even under drought (干旱) conditions, trees can often provide food and a way to earn money until the next growing season.
Some trees act as natural fertilizers. They take nitrogen (氮气) out of the air and put it in the soil. Scientists
A. Nor could the size of nearby populations, meaning people and trees can live together.
B. He says farmers are acting on their own to protect and plant trees.
C. Almost all of it is covered by trees.
D. They also help prevent soil loss and protect water supplies.
E. He devotes most of his time to making people realize its importance.
F. That is nearly half of the farmland in the world.
G. Next comes Africa south of the Sahara, followed by Southeast Asia.
【答案】
【1】F
【2】G
【3】A
【4】B
【5】D
【解析】
【语篇解读】文章介绍现在世界上农场树林占有的面积还是很多的,农民正意识到树木对人对环境的重要性。
【1】 考查上下文理解和逻辑推理。根据前面的“Researchers using satellite images found at least ten percent trees cover on more than one billion hectares of farmland.”可知,此处在说树木在农场的覆盖量的问 题,所以F项内容符合上下文。故选F。
【2】 考查上下文理解和逻辑推理。根据前后的两句话“The study found the most trees cover in South America. North Africa and West Asia have the least.”可知,树木在世界各地的覆盖率的排名。故选G。
【3】 考查上下文理解和逻辑推理。根据前后的内容可知,此处在讲述造成不同地区森林覆盖率不同 的因素,所以A项内容符合上下文。故选A。
【4】 考查上下文理解和逻辑推理。根据后面的“The problem, he says, is that policy makers and planners have been slow to recognize this and to support such efforts.”可知,问题在于政策制定者和规划者迟迟不承 认这一点,并不支持这种努力。所以,此处要将现在的农民具体是怎么做的。故选B。
【5】 考查上下文理解和逻辑推理。根据前后的内容可知,此处在讲述农民们砍伐木材做什么用途, 所以D项内容符合上下文。故选D。
【题目】(9分)下列是利用小鼠所做的几个实验,请回答相关问题:
实验一 选择30只生理状况大致相同的健康成年小鼠,测定小鼠单位时间耗氧量的平均值,以代表小鼠的物质代谢强度,将其随机分为甲、乙两组,做如下处理:
组别 | 实验处理方法 | 实验结果 |
甲 | 切除小白鼠体内的甲状腺 | 切除10天后,测得其物质代谢强度大大下降 |
乙 | 切除小白鼠体内的甲状腺,5天后,连续给小白鼠注射一定量溶于某种溶剂中的甲状腺激素 | 切除10天后,测得其物质代谢强度没有下降 |
由此可以推测:甲状腺激素能增强__________________________。为了证明这一推论,要增加一对照实验,对照实验的处理方法是________________________________________。
实验二 已知卵巢分泌的雌性激素能促进子宫发育。研究人员为探究垂体分泌的促性腺激素对卵巢和子宫发育的影响情况,用一批幼鼠做了如下实验:
组别 | 手术/处理方法 | 相同条件下喂养一段时间后,卵巢的平均重量(mg) | 相同条件下喂养一段时间后,子宫平均重量(mg) |
1 | 不做处理 | 68 | 216 |
2 | A | 36 | 93 |
3 | 切除垂体,同时定期注射适量雌性激素 | 37 | 219 |
4 | 切除垂体,同时定期注射适量促性腺激素 | 66 | 219 |
请回答:
(1)实验所用的幼鼠性别应为____________________,且小鼠的生长发育状况和个体应大小相近,原因是________________________________________。
(2)表中A处的处理方法为________________________________________。
(3)从实验结果可以看出,促性腺激素只能影响____________________的发育,第三组实验结果产生的原因是________________________________________。