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农药、化肥等农用化学物质的安全性评价须经审查同意的部门是
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美国Boston Vincent纪念医院妇产科医师Herbst注意到：于1966～1969年间该院诊断了7例年轻女性阴道腺癌病例，这是一种罕见的女性生殖系统癌症，且多发生于 50岁以上的妇女中。为详细了解这些病例从胚胎期至发病前的情况，以及她们的母亲在妊娠期的情况，Herbst将1969年Boston另一所医院发生的一个阴道透明细胞癌的 20岁女子也包括在内。这样8个病例，每个病例配4个非该病病人作对照，要求与病例在同等级病房中出生时间前后不超过5天的女婴作为对照候选人，优先选择与病例出生时间最近者为对照。对病例、对照以及她们的母亲进行随访调查。通过对8个病例与 32个对照的研究，Herbst等做出结论，母亲在妊娠早期服用己烯雌酚使她们在子宫中的女儿以后发生阴道腺癌的危险性增加。 该研究属于
板蓝根水浸液紫外灯下显
较常见外阴发育异常及畸形有
This past academic year, 146 New York City kids from 4 to 14 dutifully attended Rosalyn Chao’s Mandarin class at St. Patrick’s Old Cathedral Academy. Many of the students were first-generation Americans; for several, Mandarin would be their third language, after English and Spanish. Get used to this picture; around the world, more adults and kids are learning Chinese. Beijing is pouring money into new Confucius Institutes (Chinese language and culture centers), and two U.S. senators recently proposed spending $1.3 billion on Chinese-language programs over the next five years. From Ulan Bator to Chicago, it sometimes seems as if everyone is trying to learn the language now spoken by a fifth of the world’s population. Their reasoning is easy to understand. China is booming, and citizens around the globe want a piece of the action. Speaking Mandarin can facilitate communication with newly wealthy Chinese tourists or smooth bilateral trade relations. In a form of intense cultural diplomacy, Beijing is also promoting its films, music, art and language as never before. Front and center are the Confucius Institutes, modeled on the British Council, Germany’s Goethe Institutes or the Alliance Francaise. China’s Ministry of Education is sending thousands of language instructors to foreign programs and inviting foreign students from Asia, Africa and elsewhere to study in its universities. As a result, Beijing predicts that 100 million individuals will be studying Mandarin as a second language by the end of the decade. The U.S. Department of Education announced earlier this year that it hopes to have 5 percent of all elementary, secondary and college students enrolled in Mandarin studies by 2010. The Chinese boom hasn’t escaped criticism, however. For one thing, the language is hard, with more than 2,500 characters generally employed in daily writing and a complex tonal speaking system. Then there’s the danger that other important languages, such as Russian or Japanese, will be neglected; for example, there are now 10 times more students learning Mandarin than Japanese in the United States. And other countries fear a growing encroachment(侵蚀) of Chinese power; some Africans have complained about Beijing’s "neocolonialist(新殖民主义)" attitudes, for example, and this could breed resentment against Confucius Institutes on their soil. Yet most Mandarin students, like those at St. Pat’s, aren’t letting such concerns dissuade them. Mandarin represents a new way of thinking. Chao says that" we must begin preparing our students for the interconnected world." Accordingly, she has encouraged her Mandarin students to correspond with pen pals in Shanghai. Chao says that" in reading the Chinese students’ letters, we learned quickly that American students are far behind their Asian counterparts." If they hope to catch up to their Chinese competitors, her students--like the growing legions of Mandarin pupils around the globe -- are going to have to study hard indeed. The phrase" first-generation Americans" (Line 2, Paragraph 1) most probably means ______.
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