在蝾螈的胚胎发育过程中,早期原肠胚的细胞从一个部位移植到另一个部位时,被移植的细胞能适应新的部位并参与那里的器官形成。可是如果在原肠胚的末期,把未来将要发育为蝾螈下肢的部分,移植到另一蝾螈的胚胎,将发育为一条额外的腿。这说明( )
A. 原肠胚末期出现了细胞分化
B. 原肠胚末期已经开始了组织和器官的形成
C. 细胞是全能的
D. 原肠胚已经出现了三个胚层
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The desire to use language as a sign of national identityis a very natural one, and in result language has played a (1) ______prominent part in national moves. Men have often felt the (2) ______need to cultivate a given language to show that they aredistinctive from another race whose hegemony they resent. (3) ______At the time the United States split off from Britain, for (4) ______example, there were proposals that independence should belinguistically accepted by the use of a different language from (5) ______those of Britain. There was even one proposal that Americans (6) ______should adopt Hebrew. Others favoured the adoption ofGreek, though, as one man put it, things would certainly besimpler for Americans if they stuck on to English and made (7) ______the British learn Greek. At the end, as everyone knows, the (8) ______two countries adopted the practical and satisfactory solutionof carrying with the same language as before. (9) ______Since nearly two hundred years now, they have shown (10) ______the world that political independence and national identitycan be complete without sacrificing the enormous mutualadvantages of a common language. 6()
Questions 9 and 10 are based on the following news. At the end of the news item, you will be given 10 seconds to answer each of the two questions. Now listen to the news. According to Dr. Flores, hospitals and clinics()
A. have seen the need for hiring trained interpreters.
B. have realized the problems of language barriers.
C. have begun training their staff to be bilinguals.
D. have taken steps to provide accurate diagnosis.
The Popularity of EnglishⅠ. Present status of EnglishA. English as a native/first languageB. English as a lingua franca: a language for communicationamong people whose(1)are differentC. Number of people speaking English as a first or a second language:— 320—380 million native speakers— 250—(2)million speakers of English as a secondLanguageⅡ. Reasons for the popular use of EnglishA. (3)reasons— the Pilgrim Fathers brought the language to America;— British settlers brought the language to Australia;— English was used as a means of control in(4)B. Economic reasons— spread of(5)— language of communication in the international business communityC. (6)in international travel— use of English in travel and tourism— signs in airports— language of announcement— language of(7)D. Information exchange— use of English in the academic world— language of(8)or journal articlesE. Popular culture— pop music on(9)— films from the USAⅢ. Questions to think aboutA. Status of English in the futureB. (10)of distinct varieties of English 2()
The Popularity of EnglishⅠ. Present status of EnglishA. English as a native/first languageB. English as a lingua franca: a language for communicationamong people whose(1)are differentC. Number of people speaking English as a first or a second language:— 320—380 million native speakers— 250—(2)million speakers of English as a secondLanguageⅡ. Reasons for the popular use of EnglishA. (3)reasons— the Pilgrim Fathers brought the language to America;— British settlers brought the language to Australia;— English was used as a means of control in(4)B. Economic reasons— spread of(5)— language of communication in the international business communityC. (6)in international travel— use of English in travel and tourism— signs in airports— language of announcement— language of(7)D. Information exchange— use of English in the academic world— language of(8)or journal articlesE. Popular culture— pop music on(9)— films from the USAⅢ. Questions to think aboutA. Status of English in the futureB. (10)of distinct varieties of English 4()