问题 单项选择题 A1/A2型题

具有增生能力的柱状上皮细胞是()

A.纤毛柱状上皮细胞

B.黏液柱状上皮细胞

C.角化前细胞

D.储备细胞

E.不全角化细胞

答案

参考答案:D

解析:柱状上皮分为:①纤毛柱状上皮细胞:细胞呈圆锥形,顶端宽平,表面有密集的纤毛,染淡红色。细胞的底部尖细像豆芽根。细胞核居细胞中下部,直径8~12μm,呈卵圆形顺细胞长轴排列。染色质颗粒细而均匀,染色较淡,有时见1~2个核仁。核边清晰,两侧常与细胞边界重合。②黏液柱状上皮细胞:细胞肥大,呈卵圆形、锥形或圆柱形。胞核卵圆形,居底部,其大小、染色和纤毛柱状上皮细胞相似。胞质丰富,含大量黏液,着色浅淡而透明。有时可见胞质内有巨大黏液空泡,核被挤压至底部,呈月牙形。③储备细胞:是具有增生能力的幼稚细胞(未分化)。体积小,呈圆形、卵圆形或多角形,染色质呈均匀细颗粒状,核边清楚,常见核仁,胞质量少,略嗜碱性。

单项选择题

Actually, though, America, the "land of immigrants", has always had people of many different nationalities and languages. The 1990 census indicates that almost 14% of Americans speak a non English language at home. Yet only 3% reported that they spoke English "not well" or "not at all". That means that slightly more than one out of 10 Americans could be considered bilingual.
Besides that, many high school, college students, and even some elementary school students are required to take a foreign language as a part of their curriculum. In addition to old standbys like Spanish, German and French, more and more students are opting for Eastern European and Asian languages. Of course, not all students keep up their foreign language abilities. As the old saying goes, " If you don’t use it. " But still, a growing number of Americans are coming to appreciate the benefits of being multilingual.
Ethnic enclaves, found particularly in major metropolitan centers, have preserved the language and culture of American immigrants. Some local residents can function quite well in their native language, without having to bother learning English. Regions such as southern Florida and the Southwest have numerous Spanish speaking neighborhoods. In fact, Spanish speakers—numbering over 17 million—compose the largest non English linguistic group in America. But Chinese, Vietnamese, Italian, Polish and many other ethnic group add to the linguistic flavor of America. Foreign languages are so commonly used in some ethnic neighborhoods that visitors might think they are in another country!
Although some Americans welcome this linguistic and cultural diversity, others have begun to fear that the English language is being threatened. Since the 1980s, the "English Only" movement has sought to promote legislation which would establish English as the "official language" and restrict the use of non English language. However, some groups, including TESOL, the organization for Teachers of English to Speakers of Other Language, object to such "language restrictionism". Their view, known as "English Plus", suggests that Americans should have respect for people’s native language and help them fit into the mainstream of society. But so far, 19 states have passed English Only legislation, and the topic is the focus of an ongoing debate.
Whether or not English is the official language of the United States, it remains the "language of wider communication". Nearly everyone recognizes the need to develop proficiency in English in order to do well in America. To help those who want to brush up on their English skills, English as a Second Language (ESL) classes around. Cities with large numbers of recent immigrants often set up bilingual education programs to teach students content subjects in their native language while they improve their English. Language educators often have p and divergent views as to which approach helps learners achieve better results: a bilingual approach, an ESL approach or even a pure immersion ("sink or swim") approach. However, all these teachers share a common commitment: to help students function well in English.
Americans recognize that English is the international language, and people with good English skills can get by in many international settings. On the other hand, in a world growing increasingly smaller, second language skills can be a great favor. They can build cross cultural bridges and give people an edge in a variety of career field. Indeed, lack of foreign language proficiency can limit one’s chances for advancement and keep one in a cultural dead end street. As many people in America are discovering, being monolingual is no laughing matter.

The general idea of this passage is ______.

A.the importance of being bilingual
B.the need to speak the native languages
C.English—a language widely spoken around the world
D.the English Only movement

单项选择题