问题 选择题

我国杂交水稻专家袁隆平利用野生水稻和普通栽培水稻多次杂交,培育出高产量的杂交水稻新品种.其原理是利用了(  )

A.生态系统的多样性

B.生物种类的多样性

C.生活环境的多样性

D.基因的多样性

答案

生物多样性通常有三个层次的含义,即生物种类的多样性、基因(遗传)的多样性和生态系统的多样性.基因的多样性是指物种的种内个体或种群间的基因变化,不同物种(兔和小麦)之间基因组成差别很大,同种生物如野生水稻和栽培水稻之间基因也有差别,每个物种都是一个独特的基因库.我国动物、植物和野生亲缘种的基因多样性十分丰富,为动植物的遗传育种提供了宝贵的遗传资源.如利用野生水稻和普通栽培水稻多次杂交,培育出高产量的杂交水稻新品种.表明生物基因的多样性是培育农作物新品种的基因库.

故选D.

问答题 简答题
填空题

A good translator is by definition bilingual. The opposite is not ______(1) true, however. A born and bred bilingual will still need two__________(2) to become a translator: first, the skills and experience necessary for__________(3); second, knowledge of the field in which he or she will__________(4). The skills and experience for translation include the ability to write ______(5) in the target language, the ability to read and understand the_________(6) language material thoroughly, and the ability to work with the latest__________(7) and communication hardware and software.Does a born and bred bilingual__________(8) a better translator than someone who learned language B later in__________(9) There is no definite answer, but the following issues are important.__________(10), a born and bred bilingual often suffers from not truly knowing __________(11) language well enough to translate, with some even suffering from what __________(12) known as a lingualism, a state in which a person lacks_________(13) full, fluent command of any language. Second, born and bred bilinguals__________(14) don’’t know the culture of the target language well enough to_________(15) top-quality translations, or cannot recognize what aspects of the source language__________(16) its culture need to be treated with particular care, as they_________(17) in a sense too close to the language. And last, they often_________(18) the analytical linguistic skills to work through a sticky text.On_________(19) other hand, the acquired bilingual may not have the same in-depth _________(20) of colloquialisms, slang, and dialect that the born bilingual has. Also, the acquired bilingual will not be able to translate as readily in both directions (from B to language A and A to language B). Finally, born bilinguals often have a greater appreciation of the subtleties and nuances of both their languages than someone who learns their B language later in life can ever hope to have.