Passage Four The world population reached 6. 6 billionthis year，upfrom 6 billion in 1999. By 2025, researchers expect nearly 8 billion peoplewill be living on the planet. Ninety-nine per cent of those new inhabitantswill be in developing countries. Three million migrants are moving frompoor countries to wealthier ones each year, and increasingly, their destinationis a neighboring country in developing parts of the world. Those statisticscome from an annual demographic snapshot of global population numbers andtrends, produced by the Population Reference Bureau. Rachel Nugent, an economist with theresearch group, points to the population shifts that are occurring now fromBangladesh to India or from India, Egypt and Yemen to the Persian Gulf. She says people are moving within thedeveloping world for the same reasons they migrate to wealthier nations. “People from very poorcountries (are) going to less poor countries ,people fleeing wars and conflict.” She adds that they are also responding to population pressuresbecause, she says, “some countries are very denselypopulated, and they often have high population growth. Those people need to gosomewhere, and they are often going looking for jobs. Nugent says migration from Guatemala toMexico is one such example. “And many Guatemalans go to Mexico, probably 25,000 a year that stayand 100,000 a year that go back and forth. And that is a pretty high proportionof the Guatemalan population.” The United Nations projects that by 2050,the population of Europe, now at 750 million, will fall by 75 million；and Japan, home to 128million people, will lose 16 million. Population Reference Bureau seniordemographer and survey author Carl Haub says this is going to be a threat toeconomic health. “The number of young people in many European countries is half of thesize of their parents’ generation,” he says. “So what you see today are thecorporations, the health care system in this country saying,’Listen! We can’t find workers. We haven’t had enough workers and now we can’t findworkers’ So they will have to come from some place andthat’s going to have to come from outside the country.
Which is true about Guatemalans’ migrating to Mexico?
A、Most of them stay there permanently and become citizens.
B、They go there because of the economic depression at home.
C、Many of them go back to their own country disappointedly.
D、They go there because of the population pressure at home.
【正确答案】：D
【题目解析】：细节判断题。抓住“Guatemalan”与“Mexico”这两个关键词（在第5段）。A、B两项没有提及。从“And that is a pretty high proportion of the Guatemalan population”可知 C项错误。要证明D项正确须知第5段第一句中的“ one such example”指什么。这里的 “one such example”指前段第三句 “She adds that they are also responding to population pressures because. 中的“population pressure”（注：在做阅读理解或完形填空时要注意 代词的功能及用法）。答案为D。
