题目内容

[ A] simple
[ B ] sudden
[ C] unusual
[ D ] interestin

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The "tissue factories" in the second paragraph most probably refers to
[ A] the five genetically identical piglets.
[ B] places for the production of tissues.
[ C] animals whose organs would be used for human consumption.
[ D] animals which would be raised in quantity for transplant materials.

Text 2
A psychological issue that began to be discussed in the 1950s was the question of the most appropriate age for second language learning. The ability of young children to learn language " easily" had, from time to time, been noted in psychological literature. But in the 1950s it was the view of Penfield, a medical doctor at McGill University in Montreal, which aroused widespread attention. Partly on the basis of his scientific work as a surgeon and partly on his personal conviction, Penfield put forward the idea that childhood years offered a biological favorable stage for second language learning, and he recommended that the childhood years should be used more intensively for language training. This viewpoint, shared by a growing number of teachers, specialists, and the general public, demonstrated itself in the introduction of language teaching in the early years of schooling in several countries. The debate on this controversial issue has gone on ever since,and in spite of experimentation, some research, and endless theoretical argumentation, the issue of the best age for language learning has remained unresolved even many years after Penfield's challenge had opened up the debate.
The need for a more systematic psychological research on language learning was fully recognized and clearly expressed by Carroll in the 1950s: " We are fundamentally ignorant of the psychology of language learning. " Carrol believed that educational psychology might provide helpful answers to pedagogy (the study of teaching methods) by carrying out research on specific ques-tions of language learning,for example: "Should sounds and meanings be presented at the same time or one after the other？" "Can meanings be presented just as well by verbal definitions as by pictures and concrete materials？" " How can the transfer from speaking and understanding to reading be facilitated？" "Under what conditions does the use of native language delay or facilitate learn-ing？" " When do linguistic explanations facilitate learning？" " At what rate can new materials be in-troduced？"Following up these and similar questions, Carroll and some of his students began to in- vestigate a few of them . One of the most notable inquiries of that time was Carroll's own attempt, in collaboration with a professor of Spanish, to develop a new language aptitude test. Around the same time, studies on the social psychology of language learning were initiated by another professor and his students at McGill University in Montreal. From about 1960, in the context of emerging followers of psycholinguistics, there was a growing interest in studying second language learning
from a psychological perspective.
46. Penfield's viewpoint was met with much_________
[A] interest.
[B] controversy.
[C] compliments.
[D] encouragement.

基因型为AABBDD的个体与基因型为aabbdd的个体杂交，F₁杂合体再与3隐性亲本测交，根据测交子代表现型推断F₁产生的配子类型和比例为：
ABD 20，abd 20，abD 20，ABd 20，Abd 5，aBD 5，aBd 5，AbD 5
据此推断abd基因是否连锁，若连锁，交换值是多少？

简述四分子分析与着丝粒作图的基本原理。